We did the dining plan once, and ended up with snack credits left over. If you don't want to do two table services or a table service that takes two credits in one day, I would suggest doing what we do now.
I look at the menus online and guess what we would probably spend. Then I get disney gift cards in the months leading up to the trip, either discounted or through rewards sites. I often just buy a few here and there, too. By the time we go to disney, we have had more than enough for the food we think we will buy. We don't think about the cost when we order; this seems to be where people find the dining plan convenient. We order whatever we want. We usually do at least two character dinners per trip, and usually a table service every day. We charge the amount to the room, and pay every few days with the gift cards. I even factor in the possible tip amount into my gift card amount I save, so that is covered, too. In fact, that part was better than being on the dining plan because you still have to do your tips on the dining plan.
On my last two trips, I even had disney gift cards left over. I even used them for souvenirs, but I budgeted that into what I wanted to save on gift cards ahead of time, too. We haven't missed the dining plan at all.