when going down let say from the parking of mall of asia, is it correct to just put it in D and use the breaks?

or dapat mag-shift ako to a lower gear and use the engine break? the gears of my AT are P-R-D-S-L. Mas tama ba if I put it in L before going down? Also, masisira ba transmission ko if when i'm down already I shift back to D while in motion or should I go to a complete stop first?