In reply to mmmhumous:
> What can I do to improve the fit on the loose boot (don't think I can get them any tighter). Is an insole, extra sock, or new foot my best option? or are there any cunning tricks/gadgets for my mildly annoying predicament.
I do two things on my B3 boots. Firstly I use heel lock lacing. Google search will help you there. Normal lacing ends up tight at the shin and loose down the bottom. Heel lock lacing lets you get it tighter and more secure further down. I don't heel lock my laces till I put my crampons on. Until then I dont do up the top top hooks at all.
I use thick, just washed and tumble dried socks. When they keep their pile thick they normally stay good for a single day out. If I dry them in a dry room they loose their pile and I end up with more volume next day out so I normally stuff an extra regular sock folder up above the top of my foot.
To help getting the lacing tight at the bottom when putting crampons on I have an ice hockey lace tightener which I used when I played Ice Hockey strangely. You can get them online or sport shops. I unfolds like a bottle opener sort of and has a metal hook you can use to yank the laces from the bottom up.