The best thing I think you can do with a good pair of shoes is to take care of them, because then they will last you a very long time. The place I go to for this is Coombs, because they are a business who really knows what they're doing. The people are friendly, they've been there for a very long time, and they are patient, and give great advice regarding shoes.
I wasn't ready to give up my first pair of heels ever, which were really showing their wear/age. They repaired them, polished them, built up the heel again and replaced the inner sole too. Made them look brand new, and I was really impressed. I get a lot of my new flats with leather soles Topy-ed, so there is a rubber half-sole that prevents slippage.
Whenever I go, they always shine up my shoes, making them look much better than what they went in looking like. Their prices are reasonable, I normally pay roughly $50 for a half-sole and a fresh rubber heel resole. I cannot recommend them enough, because I have always had fantastic, friendly service here, and they don't try and talk you into more than you need. The one time I had an issue with the rubber sole peeling away, I took it back and they redid it free of charge. I've never had any other problems.