Step 1: Open a 'Cash Account' with Thinkorswim. Step 2: That is it. You're done. Note: This allows your cash to settle within the next day option trading, so you can trade 5x a week and however many times you'd like to in one single day as long as you have the cash to fund it. See the example below.
Trading Day 1: You have $1,000 in your account.
Trading Day 2: You place one trade for $100. That leaves you with $900 and you can diversify that however, you'd like.