As always with these questions it's too wide to answer accurately. The topic of "ottoman success" spreads through bout half a millennia it was a successful enterprise until it really started it's agony in the 19th century just by telling the tale what happened can and do fill volumes, without even mentioning the how and why.
So if we wanna discuss this we should take the whole topic apart into smaller groups. Maybe the most practical would be period based.
Liek, what led to the rise of the Ottomans? What shaped the circumstances they could exploit to gain prominence?