Living in Florida we spend a lot of time on our patio. We have a seating area with two chairs and a loveseat out there. It is very comfy but with two boys it seemed like the cushions were always slipping off and I was constantly fixing them. Here is an easy way to keep them in place.
1 roll of rubbery shelf liner (from Walmart)
First, remove the cushions leaving just the chair base. Next, measure and cut a piece of liner to fit the bottom of the chair. I ended up having to cut two separate pieces to fit my base seat.
Next, repeat for all chairs and loveseats. Then, replace the cushions.
Now relax and spend less time fixing slipping and sliding cushions!