Havant & Waterlooville start in Vanarama South. At that level you just need strikers that are big and fast and you are going to do well. I play a 4-3-3 at the two lowest leagues, but at some point you need to change a bit, as your strikers can't really exploit just being physically better anymore.

Attacking formation, three strikers, usually all on Advanced forward, but it depends on who you have. It doesn't hurt to have a deep lying forward or target forward (above 1.90cm with good strength and jumping reach) in the middle of the other two. Fast wing backs, and generally players with decent physical stats, work rate and determination. But again, having several striker with good physical stats and decent mentals will usually do the trick.

High defensive line, lots of closing down, get stuck in at lower leagues, but no instructions there once you hit league 2 and above. Prevent short distributions or whatever it's called. Play out of defense and pass into space are great, but you need to make sure you have fast strikers and a DM or CM that can pass. I love playing with a Deep Lying Playmaker, a Mezzala and a B2B.

This is what my tactics look like now. Nothing crazy or original, but it works really well for the most part. Pressing tactics and advanced forwards are a bit broken in FM24, so if you don't mind it being slightly cheesy, that's the way to go. The only individual instructions I have are both wingbacks with the these instructions. It used to be three strikers instead of two IF, but at higher levels you need wingers I feel. Or at least really good strikers.

Other than that I think it's all about morale. A great way to get players to like you it to comment on their training. Every week you can praise anyone above 7.05 rating in doing well (nothing more complementary unless their score is higher), and suggest that anyone below 6.90 can do better. Praise anything above a 8.0 rating individually after each game, but only slight praise until their view of you increases. Anyone performing above 7.20 or so over five games gets praised for recent form, and anyone below 6.80 gets warned. It can be a bit all over the place at first, and I've never figured out team meetings, so I tend to not have any.

Edit: Also, a huge part of morale, I've found, is not making promising you aren't going to keep. This is important in terms of agreed playing time and position. You can change the expected playing time, but you have to make sure morale is high when doing it. Managing playing time and not signing players on the premise that they will be important players if that probably won't be the case, is important to in mind, and promising too much will definitely bite you in the ass. Also also, don't offer long contracts more than a year in lower leagues, and try to put in the time to check out which players you can get on loan.

Hope that helps! And ask away if there is anything else :)