Yep, sounds like classic over-pronation blistering. If you are using any kind of motion control shoe then as your foot lands the arch rubs against the 'support' part of the shoe.
I suffer from this and always have - I generally run in Brooks Beast, although did try switching to Adidas motion control, but they were terrible.
Things that I find help:
Thorlos are about the only socks for me
I use compeed plasters prior to a race or important long run, but I put them on about 36 hours before the run to let them set, and I always warm them up between my hands for a couple of minutes before putting them on - it helps them stick. If you put them on before a run then they just tend to fall off
I used to put vaseline on my feet, but this rubbed off after a few miles. Compeed have brought out an 'anti-blister' stick which is a bit like a solid deodorant that you rub on your feet and seems to last longer than vaseline. You can get it from a decent sized Boots, it's with the foot stuff
Running on a camber definately makes mine worse, so try to avoid heavily cambered roads/pavements, especially ones with a lot of drives cutting accross the pavement. Basically the camber accentuates the movement of the foot
Whe I do get a blister I have a very sharp cuticle scissors that I use to snip the looses skin open - just a tiny cut of a few millimetres, enough to drain the fluid/blood. Make sure you get it all out, and then just put a small plaster over the snip for a few hours to keep it clean. This will help the skin to harden and speeds up healing.
You all have my sympathy, I hate my blisters but have just come to accept them. Every now and then I get a long run without a blister, generally when I can run on a flat surface (Hills are fine, as long as the running surface is level). For the FLM this year I used a couple of compeeds along with the stick thing and only got 1 blister about the size of a 5p.
