There's loads of factors which make each individual thing different.
Depends on the run up to the object, how high it is, how much room there is on top, what you plan on doing when you get onto it, what you in particular are best at doing, the list goes on.
I personally tend to find if it's something quite high, say 3ft+, I try to bunnyhop up if the run ups right whereas lower things I'll probably try and half pedal up.
Though I haven't had any practice really at sidehopping up stuff or backhopping to front and wheel transfering so I have to stick with my strong points currently.
Just do what feels right for you and the object at hand!