It’s ridiculously simple, but I love my Universal Quick Release Adapter. I can’t find anything like it here in Australia; this one was bought in a national chain in the UK called Jessops and sent by kind relatives. It’s not perfect but it does the job, making mounting and unmounting gear simple. Since one of the key differences between cheap and pro gear is the hassle of using a coin-driven tripod screw, this is an inexpensive equaliser.
Since the best gear is the stuff you actually have with you, buy more than one, to provide a base for each of your tripods and a top for each camera. Then, you can easily switch between multiple supports. On a day out, I can actually carry my basic monopod and flexible Gorillapod clone (from Aldi!) and snap either to my 550D in seconds. Hugely useful and it doesn’t tie you to a particular brand of tripods.
Note: The picture shown on the link above is incomplete, as that’s only the bottom half of the assembly. The top half stays plugged into your camera and the bottom half stays on the tripod.