Disclaimer...only my take on fitting..
Use thick toe Caps!! ...For more volume and for hot spots I always bake, .. the hot rice did not seem to effectively heat the whole liner especially when adjusting for ankle and other outer bumps in bones...but that's my experience. If your not fast and have your foot all taped up with all the added hot spot foam in place(I tape mine in place) and have sock on ready to go...then don't bake as you really need to be pretty quick..
Liners can be re-baked a number of times, so if you do it yourself,,,you'll quickly learn on the one foot what went wrong.. also don't forget the block of wood (2X4) under the ball of your foot under the boot after you buckle it down.. kick the heel down then stand on it ...forces the heel in the pocket..you should feel it sit real nice in there...
Oh and don't bake with your footbeds in the liners.....
There is a lot of youtube video out there...on both methods.
BTW those liners should have had good room in the toes... I'm a size 10+