Where I am there’s no CARs. So below the 6th tier mens and 4th youth, you are on your own.
7th tier mens can be tough. There are essentially two successful approaches I have seen.
One way, stay central, far from play and take decisions at distance - and adopt traditional positions at corners. Basically this is a low risk approach, minimal use of the diagonal. This works for some people. Needs geometric judgement of offside. Can look a bit ”centre circle” and some calls will be reactive guesses.
The other way is to use the diagonal to the extreme, take up wider positions to see the offside line. This is high risk, involves a lot more movement. Vary positions at corners, even use the goal line. This only works if you can run and keep up with or outrun the players. You can make great credible offside calls. But you need to be really alert to breakaways and adapt if the players are better than expected!
I do the later. But it’s in a league where I played for years, I can anticipate the risks and I can run.
Of course, YMMV.