Another way to easily remember the arrows is to associate them with words: ^ with the A of and, and v with the V for vel (Latin for or). I always did this in logic class since I would always get confused otherwise.
I remembered these and union/intersection sign by imagining balls falling on the symbols from above - in case of V (OR) they would end up inside the symbol, which suggest summing/union, and in case of ^ (AND) they would get split and collect on opposite sides.
Also useful is making the arrows round-ended makes the the union/intersection signs, with or being union and and bring intersection (as it would be with the corresponding indicator functions).