My favorite commercial right now is the Citi one with the girl complaining that her new boyfriend is just using her for points.
Here is the youtube clip: http://www.youtube.com/watch?v=Qxq71tsJz10
I don't think Citi is the right way to do it, but dining is an interesting place to stack rewards, one I don't utilize enough. If you have a category bonus card, you can of course buy gift cards to your favourite chains at grocery or gas stations to get category bonuses. For example, the Chase Freedom bonus is currently at gas stations, and their points transfer to Chase UR, which to me are worth about two cents each, meaning you are earning almost ten cents back on every dining dollar.
Always make a rez on +OpenTable if you can, they have some loyalty points also.
If you are a waiter at one of these chains, you can do some real magic. Buy gift cards to your own restaurant and whenever someone pays cash, use the giftcards to settle up with the restaurant. Just don't tell management, they might get annoyed. At +GiftCardRescue and +eBay , you can find these cards discounted as well. If you buy them online, make sure to use evreward.com to get the best cash back on the purchase of the gift card.
However, if you haven't hit the signup bonuses for all the dining loyalty programs, you should do that first. It seems everyone uses the same loyalty program vendor, rewards network. Here are the logos on their page:
Many of these offer a signup bonus, and those can vary over time. Make sure to get all the signup bonuses! There are several airlines and several hotels and then some random junk I am not familiar with.
The way it works is you just register your credit card and they occasionally give you more points. When you register your card with one, it seems to de-register at the others. Hit all the bonuses and then choose your favorite program (Dividend Miles for me). The selection of restaurants these are good at is fairly wide. They are the same at each program, so hopefully you can find a favorite near you. I randomly seem to get extra points just from going out a lot.
There are a few other things you can do as well, sync your amex card to social media, sign up for +Upromise by Sallie Mae and register your card, check google offers for offers you can redeem with just your phone or credit card (eg this one in Midtown), and a few more. Offermatic and Envaulted appear to be dead companies.
To recap, one potential bonus stack:
Rewardsnetwork.com Dining Loyalty Program
Social media / coupon discounts
CC points (eg CSP 2 points in dining)
Another potential bonus stack only for chain restaurants:
CC bonus for buying gift cards online
Evreward determined online shopping rebate
Social media / coupon discounts at the restaurant