If you're not at risk of war, you can be really crazy and do this:
Go to your budget, and drag the "Population" bar all the way to the right.
(Might as well do "Economy" too)
Spam through a TON of turns. (like, multiple hundred)
Put everything back to normal.
You'll be in debt, but you can spam turns back to a balanced budget.
(Also, if you have enough money and movement points, you can always conscript from the same territory multiple times to get more armies.)
(It also helps if your stability is high. Try assimilating provinces with low stability (below 75%)