>>981625Depends totally on your feet and person to be honest.
I went to a flashy sports store and bought this pair of insoles for my specific size and foot arch,
>http://www.sidassport.com/nos-produits/running/semelle-3feet-activ-mid-400-2.htmlIn hard foam / gel combo or whatever it is (construction is hard foam but has a gel part at the heel). Still a bit to hard to march on asphalt but my feet are very comfortable in my shitty non ergonomic china boots thanks to them. Top fabric got loose after 4 weeks of commuting use though, so its hard to recommend a 30€ "quality" insole thanks to that. So just go to a shop that either specializes in foot care or that has big focus on shoes and insoles and try out models until you find one that fits nicely in your boot (a major annoyance in the fit will stay, a minor annoyance in fit will most likely go away after a few usages).
If you gonna stand still or move around in urban areas more then I think you should try out a gel insole.
If you are only out in nature then a hard foam insole will do.
And the foam/gel combo is better than both in 80% of all circumstances but costs twice as much.
Don't dwindle to much on it though, just buy and try until you find one that fits your feet and walking style primarily.
If you have trouble with your feet/legs then you should probably try out two insoles at the same time, one that is hard foam and one that is gel.