This job was don quite a while ago and it has been one of the best investments I've put into my home.

Underneath the T&G OSB, I have a product called DELTA-FL.

I went with this method instead of the DRI-CORE 2x2  squares that are typically sold in big box stores. This way turned out to cost me 1/3 less.

This raised the floor by approx 1 1/2", leaving me plenty of head room still.

The DELTA-FL can be seen in this photo.

I then started laying T&G laminate flooring.

If you have any questions, please do ask away.