Products like Ammo, Summer Ammo, IO and IG are maybe more suitable around the younger ones, whilst TUTH, IH and A314 can suit the older ones better.
Secondaries like Instant Shine, P83, P74 and P75 (in small doses) are useful across the board.
We can’t really say what dose you should use as individual personal and situational matters are involved - You need to do some testing to see what suits you best.
For application points, see this thread:
But don’t get too caught-up with them - so long as it has decent blood flow and is open to the air to diffuse, its a viable point. 