If you want to use toe clips without the straps, use the half clips. I run full toe clips with straps, you don't have to snug them down for city riding, I run half clips on my upright city bikes, and I run platform pedals on some others.

FWIW I use the half clips with work boots, running shoes and dress shoes (I have leather covers on the half clips). For the full toe clips I am usually wearing a pair of stiff soled shoes that are similar to indoor soccer shoes, they don't work as well for boots or bulky shoes.

Aaron