What causes more dry skin? Gel or foam? What's better if you have sensitive skin?

I have sensitive skin and i was wondering, which one is better to use. I shave only once a week. Sundays only. The reason for this is, my beard grows SLOWLY, but i wanted to know which is better for my face because for some reason every time i shave i get some small spots and my skin feels weird. It makes me feel uncomfortable. Does anyone feel the same? Any suggestions to stop this?