@Sara-S It's possibly easier than on fabric! I used a medium weight cut away stabiliser, and just the normal needle. I hooped the stabiliser then used temporary spray adhesive to float the leather on top.
Speaking of temp adhesive spray, I've realised that you need to spray it on the stabiliser, not the leather/fabric, as it stays sticky on the one you spray it on, but not sticky on the fabric when you peel it off - if that makes sense!