Check the foundationless hive every 2 or 3 days. It's easier to fit comb when it's brand new. It the hive is level, it shouldn't be much of a problem. If you hung your queen between the center frames, they'll more than likely start building the comb on the center frames.
Once the two middle frames are more than 1/2 drawn and have larvae, and it's warm, pull an empty frame from one side of the box and put it in the middle. The bees will draw the frame pretty fast and with two drawn frames beside it, the odds are that it'll be straight as well.
The following week, grab an empty frame from the other side of the box and do the same thing. It won't take long before you have a box full of nice, straight foundationless frames.