I'm 10 months sober !
The key thing for me has been having a good support system and making sure alcohol is not easily accessible to me. I also replaced my bad coping mechanisms (e.g. alcohol, weed, clubbing) with actual coping skills I learned in therapy. I know therapy is not super accessible, so I do want to add this also works with other coping mechanisms such as exercise, playing video games, reading, honestly just distracting myself until the urge/flare up passes.
And when those don't work I just kind of forbid myself to move, call someone, or go to sleep. Just letting that urge pass is the important thing. It does help to have at least one person who is aware that you're trying to be sober who you can call or be around - they don't have to be strict with you, I've found its been better to say to my friends 'look, I'm trying not to drink and would appreciate some help, but if I do drink, do not say anything about it, because it is my responsibility and choice and if I decide to drink I don't want to feel worse about it '. This allows for me to have support but also not feel ashamed or embarrassed if I do relapse because I know they won't judge.
Other important things for me are :
-Living alone, or with someone who doesn't drink regularly, if possible. I've always lived in a house where at least one person i lived with would drink something like a glass of wine almost every night. And then as I started trying to go sober, I actually broke my contract and moved out of the flat I was sharing with my friend because the first week we lived together I drank like 3 or 4 times, purely because he was drinking. I stayed with my partner a lot during lockdown and they don't drink, so that was actually super helpful and it made me almost embarrassed when I did want to drink when I was just doing nothing at home, and that forced me to reflect on how normalised alcohol has been throughout my life and how that was holding me back. It is also helpful that my partner keeps all alcohol they do have in a big box on top of some shelves that I both can't reach and am not strong enough to lift so I can't actually access it. I now live alone and alcohol is not allowed in my flat and it's made it SO much easier. I think this may have been what's helped me the most, actually. But it kinda ties in with making sure alcohol is not easily accessible.
-J2Os. Every single time I have a strong urge to drink, and either my healthy coping mechanisms aren't working, or I'm in public or something, I get a J2O. I think it's because drinking from a glass bottle just helps me, also I love J2Os. This also works with non alcoholic cider or just whatever non alcoholic beverage you like, just get something to drink. One time I didn't have any J2O so I mixed coke and orange juice in a wine glass and drank it just because it was quite gross but in the way alcohol is gross. So that kind of just made me realise I was drinking things that didn't even taste nice just for a feeling that I didn't actually even like having but was addicted to. I know that sounds a bit wild but it did help me. And personally it helps me to drink from a glass bottle or wine glass but that might just be a me thing.
-Having someone who doesn't drink or is trying to be sober who you can talk to. My mum actually went sober around the same time as I did. Unfortunately she did relapse and hasn't quite got herself back sober again, but she does drink way less than she used to still! And she does want to be sober so it does still help to talk to her. My partner is also good to talk to as they don't like alcohol either (only drink socially, and only on like big nights out or events) and if I start wanting to drink they'll remind me that alcohol doesn't taste nice, I don't actually like the feeling (even though the addiction has convinced me I do) and life is so much better without hangovers.
-Not being strict at first. I am way more strict with myself now, but when I first started trying to be sober, I would drink more purely just because I hated having the pressure of being sober and I tend to rebel against strict pressures and rules, even when I'm the one enforcing it on myself. So for a year or so I was 'sober, but could drink if I wanted to' ,which I know isn't 'being sober' but it relieved pressure so much that I was able to massively cut down on my drinking. And I only decided to be fully sober 10 months ago, at my friend's birthday, because I pprued myself a glass of wine and drank some and then just realised I didn't like it. I didn't want to drink or be drunk I just felt like I had to for some reason. So I poured it down the sink and haven't drank since. I think not being so harsh on myself for the first year has helped me to remain fully sober when I was ready to be. I know this may not work for everyone but if you're like me and rebel against any kind of strict rule it could help!
Sorry this was so long ! There's definitely other things that have helped so I'll come back and add some if I remember but hopefully at least one of these can be useful. Good luck !
TL;DR - support system, replacing bad coping skills with healthy ones, distracting yourself, making sure alcohol is not easily accessible, living alone or with someone who doesn't drink, finding a replacement drink (mine is J2O), not being too strict or hard on yourself.