yes! get weight on a snake before changing things up, so then they have a little extra fat to keep them tided over if they aren't interested.

Some of my snakes were much better about taking FT after they'd already eaten a live mouse in the same feeding. Of course, you will want to get yours to the point of eating more than one live at a time. But it seems like if they were in eating mode after a live one, they would attack the warmed up FT's more than if offered one first.