Hi,
Well I guess the question has to do with when you start the shoves and under what circumstances. And that depends on many, many factors for me, like cards, position, itm/bubble, icm, pre flop action, image of other players who took part in the preflop action, my strategy for that exact tournament, even my psychology on that exact day, and the list goes on.
All these factors can lead to situations like shoving with 15 or 20 bb or even waiting until I have like 3 bb because the circumstances were such bad that I couldn't do otherwise.
Generally my plan is to start shoving when I have 10 bb and I'm the first who opens the pot, with hands like KJ+, A8s, A10o, 22+. And getting a bit looser the later my position is, like A5o, K10o, QJo from the button or sometimes any King from sb.
I'm definitely not the guy who shoves 6bb with 45s from anywhere like the op said 3 years ago xD, but that's just me.
For example 10bb and KQo with a loose limper or raiser is a shove for me, but with a solid raiser is a fold. 45s is always fold unless I am the sb against the bb with 2bb left xD.
But again, all depends.