I'm smacking myself on this one....

A while ago I built some shelving and got it fitted with plywood, ensuring that the plywood was flush at the front and ended halfway on the joist before starting the next sheet. However, for the life of me (it was a while ago), I cannot figure out how I did it.

I'm looking to build a 10x16' shed. I have framed everything out in Sketchup, and all is going well. However, without exhibiting waster, I cannot figure out how to get the plywood to land on the center of the joists, making sure every edge of the plywood is secure.

The floor frame will have 2x6s, 12" on center. When I lay down a 4x8 sheet in sketchup. it covers 8 joists, completely. Therefore, when I go to add my second sheet of ply, the connecting edge has no support.

I figured I could trim 3/4" off of the first sheet, allowing me to hit 7.5 joists, but then I will be short on the other end...what secret am I missing that is making this way more complicated that it should be?

It's quite embarrassing that I can frame out the entire building....but fail at the floor sheating

Any clarification would be appreciated!