I don't quite fit the requirements but I might be able to help anyway. I have a list of things that I think about before the game starts -

1) Matchups in general, anything I can think of and any predictions I can make about lanes stuff like obvious pushers (graves) etc..
2) Based on that information I try to figure out where I want to gank early and then I think about where my enemy would want to gank early. (Remember though, you should always be willing to adapt your plans when in game, if someone overextends or you can countergank you should do it)
3) Can we 2v2 top? (Consider at level 3/6)
4) Can we 3v3, 4v4 bot?
5) Think about what jungle route their jungler will take and whether or not they can fight you in an even fight.

As for my jungle route, if I think I can gank mid or bot I do a botside half clear and then go to crab. If I think I can gank top I do a small camp > buff > buff > gank. If I think I'll struggle to gank I'll just full clear, again watch out for counterganks and stuff though when fullclearing. If I expect an invade and I'm blue side I'll do krugs > ward red > do raptors and if no one comes I'll go back to red, you get to smite red as well so that's always fun.

Invading is highly situational, if your laners are pushed under tower you should likely avoid invading and if their laners are pushed under tower, go for it. If you see them low, invade. If you have an item advantage, invade. If your champ is stronger, invade. If you can't gank and think you can fight them invade.

No tips you wont already know and my mid/late game decision making is mediocre. I can play in the fights well but I can never pick the right fights.