I did a leak detection today on a liner we installed in 2006 (about 10 holes or so), There were scrapes and punctures along the coves of the pool especially in the shallow end. Take this advise....
wrap the ends of your pool brush in thick wads of duct tape; even though the edges are plastic they can get burs quickly if they touch the concrete. (see picture)
Replace your brushes on your vacuum head when they are worn and inspect it to make sure there are no rough spots (rub your hands all over it).
Also when you get a new liner installed or if you are installing the liner for someone else please make sure to keep the large piece of vinyl left over from cutting out the step area (if applicable). It is very useful for patching as it will match the pool exactly unless your liner is starting to fade.