So, in case you are in the market for a new phone, and are confused by which phone to buy, here are some tips. It is a long read, so don't expect a TL;dr.
1. Brand name - Check if the brand is popular in your Country. The more popular it is, the better the quality could be, since it is likely to have issues.
2. Service Center and Support - Search around reddit or other websites to see what kind of service you can expect from the company which makes the phone. It may sound surprising, but the biggest OEMs can sometimes offer terrible support.
3. Budget - Always have a budget in mind, before looking for a phone. Learn to accept that you cannot expect flagship devices in a low or mid-range device (Helps in avoiding buyer's guilt post purchasing). Don't cross your budget needlessly for a gimmicky feature, or because a new phone with an extra feature has been launched. Most mid-range devices get outdated within a few months.
4. Memory - More RAM does not mean more performance. Do not buy a 6GB RAM phone if a 4GB or 3GB RAM phone is more affordable. It is the processor that is the real power behind a phone, and the OS too of course.
5. Processor - Do you want ROMs? Go for a Qualcomm Snapdragon device. Why? Well MediaTek never open sources the drivers and code needed for making ROMs. If you can find no other phone in your budget, then you can go for a MediaTek device.
6. Snapdragon 4xx or 6xx or 8xx - Snapdragon 4xx devices are low range and cost less. You may get better battery life because it uses less power. Snapdragon 600 phones are performing almost as good as 800 series these days. You will only notice the difference when you actually use a higher end phone.
7. Battery – Do you want a big battery or fast charging? Pick one and go for it. For some reason, OEMs think a slim device is better, and these devices have smaller batteries. But hey there is fast charging, it's so cool. It becomes useless if you have no access to a charging port (e.g: when you are travelling, or in case of outages).
8. Camera - Do you need a dual camera phone? Is portrait mode important to you? Such cameras may not always be available in your budget. So be prepared to spend a little extra. If you don't take many photos, you can probably find a decent camera within your budget.
9. Beware of gimmicks - Don't fall for gimmicks like 24 MP camera, or world's best selfie phone, or whatever. Be the geek and analyze, what is the camera's aperture size, what sensor does the camera use (Hint: Sony sensors are the best).
10. Band support - If you are ordering the device from abroad, say you are buying a phone from China, and you are located in the U.S, the phone may not work in your Country. So, check with your carrier what LTE Bands they support, and check the technical specifications on the phone manufacturer's website before ordering it.
11. Accessories - Many devices, especially in the low and mid-range segment don't have many (or in some cases, any) accessories available. So, Google for the phone's name and the accessory you want to buy and see what you can find. For e.g: Redmi Note 4 Flip Cover, or OnePlus 5 Tempered Glass, or something like that.
12. Purpose - Are you buying the phone just because you want a new phone? What is wrong with your current phone? Have you tried servicing it? Don’t buy a phone because you want to. Only buy a phone, if you absolutely have to.
13. Usage – Are you a casual user who uses the phone for calls, texting (SMS), instant messaging (WhatsApp, Viber, Telegram), emails, browsing, Facebook, Twitter? Any phone will do for you. Are you a gamer? If so you need a powerful phone (Snapdragon 600 or 800 series to play without lags) and a large screen display (5.5-inch) with a high resolution (1080p Full HD for a crisp picture). Do you watch a lot of movies? You still need a large screen with a 1080p resolution or above.
14. Dual SIM or Single SIM: Do you need to use two SIM cards? Or are you cool with using a single SIM card. Some devices have Hybrid SIM card slots, which let you use one SIM and a microSD card slot. Some devices even offer triple card systems, where you can use 2 SIMs and a microSD card. Dual SIM Dual Standby is also something to look out for.
15. Memory Card: If you need microSD support on a phone (or USB OTG), please check the specifications before buying the device. On the other hand, you probably don't need one on a device, with 64GB or 128GB of internal memory.
16. Design: Do you want to use the phone in one hand? A device which has an 18:9 aspect ratio with a bezel-less full screen display is the trend these days. So, decide what kind of phone you want.
17. Expected usage life: How many years will you use the phone for? Some people like buying a new phone every year, which I don't understand at all. Some people buy devices and use them for 5 years, or until it stops working. If you buy a mid-range phone, you can expect it to work well for 3-5 years, though it may be quickly outdated. A flagship can also last 5 years. It all depends on your purchasing power. Again, do not upgrade unless you cannot repair your device.
18. Must have features: Fingerprint scanner is a must for additional security (even for unlocking certain apps like Authy, LastPass, etc). Most devices do come with a fingerprint scanner these days, unless it is a low-end phone.
19. Audio (music) – A 3.5 mm jack is always good. Don't let OEMs fool you, the good ol' headphone jack ain't going anywhere. What you should check for, is what DAC a device has, and this unfortunately is something most OEMs don't mention. The reason? They are using the one which is in the SoC, nothing special.
20. Speakers (loudness) – A high volume speaker is always good, especially when travelling or at home while watching a movie, or something, when you could easily miss a call. A loud performing speaker is also useful for gaming or binge watching movies, YouTube or music.
There you go, pick a phone and see how many of these points it checks with, and that should help you decide. Some of these tips can also be used for deciding what tablet to buy.
This is more of a geeky list, but we are GEEKS. If you are tech savvy and care more about the OS experience, these are some things you want to look out for.
1. OS Updates - Android's Kobayashi Maru, is without a doubt, OS updates. So, do your homework, and check the OEM's history of updates. Most Android devices receive one year to two years of updates. But it is not always the case. Some phones get 0 updates, and some OEMs abandon software support for their flagships in less than 2 years. (I'm looking at you OnePlus).
So, in case you want a phone with 2 years of updates, you may want to look at the budget friendly Android One (Mi A1) or the expensive Pixel 2 or Pixel 2 XL series.
2. Stock OS vs Custom Android versions – I hate custom Android skins like MIUI, EMUI, Zen UI etc, which not only take the look of stock Android away, but also add in useless features like RAM cleaner, Antivirus, Booster and other nonsense.
3. ROMs – A life saver when the OEM abandons software support, and also when your phone has a terrible UI. A phone with good developer support might last many many years. (OnePlus One, Moto G 1st Gen, Nexus devices are good examples). ROMs are also a great way to temporarily get a latest version of Android, before the OEM releases an update officially.
4. Developer support (also includes ROMS, Root, ad blocking, unlocking the boot loader, TWRP recovery) - Not to sound like Treebeard, but don't be hasty. Wait for a month or two before buying a device. You may see many ROMs for the device on websites like XDA. If a device doesn't have ROMs even after 3 to 6 months, I'd say don't buy the phone.
Some companies like Xiaomi make unlocking the bootloader a real headache. But most Xiaomi devices have tons of ROMs available. It all depends on how popular a phone is.
5. Warranty support for unlocked devices – Some OEMs play cool even when the device is unlocked. In most cases, you can always relock the phone, but in rare circumstances you can't (curse Samsung Knox though it does provide great security). Let's say you have a phone which won’t boot (hard-bricked), you can't relock the phone. So, make sure to read the terms and services, and if you are polite, they may help you for free even if you have indeed voided the warranty.