I like to put Pop Overs inside portal rows, so when you click on them, rather than going to the related record. You stay in the same layout. In the pop over you can fit way more fields than what shows in the portal row, in fact you can place just about the entire layout in the pop over.
That all said, when the relationship is set to allow creation of a related record. The entry row is always at the bottom. Makes for a pain when there are more related records the rows in the layout.
My Idea is to move the creation row so it is always on the top of the portal. Now when you click in a row or in the pop over all the fields inside are blank until you start typing in one of the fields. This pop over stays open until you close. I have even added buttons inside to do such things as start or stop a task timer.