Come on master, give us some of your tips, framing these little blighters is quite tricky !
OK Grasshopper.
Solid tripod.... essential.
Gimbal head.... Perhaps not essential but highly desirable, and gets essential as the lenses get longer. I don't really think of the tripod as avoiding camera shake - more as a sort of gun platform to enable smooth tracking of the bird and this is where the gimbal head pays dividends. You really need to get the single AF point over the head of the bird to guarantee a sharp shot and DOF gets less as the lenses get longer.
Trying to hand hold a heavy lens and keep that singe AF point over the eye of the bird is well nigh impossible and it wont be long before you're dithering like a jelly. A gimbal head makes this much easier... you can keep the AF point where you want it with no stress and wait for that nice pose or opportune still(ish) moment to press the shutter.
Using a solid tripod and a gimbal head will show immediate improvement in your shots probably more than any other single thing. I cant over emphasis the benefits!! I use the gimbal head with the 500L, 100-400L the 70-200 2.8L and even the 180L macro. Once the camera/ lens combo is balanced on the head around it's centre of gravity you can point the camera where you like - virtually with one finger.
Long lenses are an obvious advantage, but they're no magic answer to great shots - you'll still need to get much closer than you think to really resolve that fine feather detail.
That's the bones of it really. The rest is down to a bit of guile and getting those birds to land within range and preferably in a nice photogenic setting. In a garden setting it's easy to get the odds on your side with a bit of careful planning and preparation.
I always shoot in Servo AF Mode... one AF point enabled.