Offer your advice on anything. Simply state helpful advice that you know of for whatever you like! It can be as simple or as complex as you want, you never know, you might learn something! Or maybe remember something better!
I reckon this thread is going to die a painful death.
I'll start with two mathematical pieces of advice:
-BODMAS (Brackets Over Division, Multiplication, Addition, Subtraction)
Incredibly basic, got told it absolutely years ago about how to remember what operation to do first.
-SOHCAHTOA (Sin(x) = Opposite / Hypotenuse, Cos(x) = Adjacent / Hypotenuse, Tan(x) = Opposite / Adjacent)
This is a useful acronym to help you remember trigonometry!