Wide receivers are plentiful, which means there's always SOMEONE on the waiver wire with a decent matchup. Of course, spotting that free agent player each week is a bit of a psychic trick.
My approach this year? I'm focusing on the receivers that are available in the first four rounds, and I want at least two of them. A nice third receiver would be a bonus, but beyond that? They're mostly roster fillers, to be swapped out with waiver-wire pickups as the season progresses.