I've already discussed protoss v zerg briefly, though, I'm not gonna tell you what to do mid-late game since every game changes. That comes with experience(learning what to do).
On to protoss vs terran.
Just do the standard 1 gate goon obs build. Personally, I don't like this build and prefer 2 gate ranged goons over this because it's alot stronger. But, it's tricky on a map like lotem where you need shuttles to defend your cliff.
Anyway, the idea is to outresource/outmacro terran, use flanks, etc.
The units you'll be using for the most are dragoons, zealots, shuttles and obs. Late game carriers are nice if you can micro. You could even throw in temps for storm drops or using hallucination on zeals to help absorb mines and break pushes. Dts are also useful. Use your imagination. You could even try sair/dweb/goon, really. Don't expect too much,though since d-web received a big nerf.
This concludes my pvt synopsis.