Hi Camille, i get blisters when i go backpacking. My trick is to use the bandaid blister bandaids and then put athletic tape over the bandaids. Also i have heard that petroleum jelly on your trouble spots works. I am going to try that next. Hth.
Have you seen this trick about creating a 'heel-lock' with the top hole of your laces? You can Google it and there are a couple videos. This link probably won't be a clickable link cuz skimble is great like that.
But yeah i saw it a while ago and found it again by googling something like 'what to do with that last hole in sneakers'... There are a few results.
I haven't needed or tried it but for you it might be worth a try