A bit off topic, but my margin is conservatively set at $12500 / contract (for ES). So when a method yields that much $, I add another contract.
12.5k / 1 contract, at 1000 ticks, account =25k, now trade 2
25k / 2 contracts, at 500 ticks, account =37.5k, trade 3
37.5k / 3 contracts, at 333...