This not-buying-shoes policy, Drince.  I don't like it.
I bought two pair myself, both for serious walking.  My fit issue is a B-width foot with a very narrow heel so everything with a back slips.  Solution?  The very good salesguy at the Mall of America's The Walking Company found two.
Exhibit 1:  the velcro strap at the back 
 
Now, normally I would not wear a Mary Jane but I am desperate enough to compromise.  You know, the shoe really looks okay on.  Who knew.
Exhibit 2:  the heel strap
 
The salesguy kept calling these 
gladiator sandals.  I don't see it but I did take a really long walk in them yesterday.  No blisters, very comfortable, and pretty nice looking, too.