How to fill a rectangular hole with an even amount of vertices on either side? I tried crating faces but it left missing edges. In the end I was left with all the right lines but there was no vertex in the center.



Here's a follow up image in case you're wondering what I mean. Notice how there's no vertex in the center.
If both sides have the same number of vertices, you can quickly do this by using the Grid Fill tool (CtrlF > Grid Fill) and tweaking the operator settings. A Span and Offset of 2 should do the trick.