Why not consider going out on Friday, returning Monday evening? You still get the weekend, but you trade a Friday night for a Sunday night...
I know a few people who thought they had a great deal taking Ryanair to Brussels and then training / bussing up to Holland. Almost all said they would never do it again, as it took up most of the useful time of their weekend.
If you're heading for Schiphol and are based North of Dublin, you could consider going from Belfast - easyjet go direct, but their fares are generally as expensive if not more expensive than aerlingus.