Sure, in theory, a trade at X # of contracts will work just as well at 10X in most markets. But when it comes to one's own individual account (as opposed to opm), preservation must be your ultimate priority.
When you trade in a market where the typical leverage allowed, if fully utilized, can either double you up or blow you out within a session or 2, you must "structure" your use of leverage, for lack of a better word -- and there really is no hard and fast rule for this other than your own tolerance for performance volatility. Equity traders can get away with being alot sloppier in this regard, but that is just a function of having less rope to hang oneself with.
I think most traders on their way up tend to have certain "breakout" trades that get them over successive hurdles; after a number of these breakthroughs then it becomes just a matter of figures. But I think in the end traders tend to just grow into larger positions once every so often, kinda like how a spider or crab molts.