Preventive measures for roaches

So I live in North Alabama where American roaches are pretty common but we moved to an area in our city where they are way more active. We moved here September and I was killing at least 1 a week and when I walked outside at night you'd see at least 5 scurrying about. Now that it's cold out activity has dropped exponentially. I think i've only seen one make its way inside in the last month and I'm pretty sure it was because we had a leaky fridge. Anyway I'm just looking for some preventative measures to implement now to insure they aren't so active once it starts heating up outside again. We rent a house so we're a little limited on what we can do but anything will help.