One of the best exercises with resistance bands are triceps pushdowns. It feels great, and works great. The only thing is, you will need a door anchor to do them, and many resistance bands you get at the store do not include a door anchor. So, before you buy some, check out the best exercise bands to buy, because you'll definitely want a set that includes a door anchor. Without a door anchor, you'll be missing out on a lot of great exercises, such as triceps pushdowns.
To do this exercise, position the door anchor at the top of the door and then slide a resistance band through it's loop. Now, you can either attach handles or use the handles if they are fixed to the band, but that isn't ideal. The problem with this is that the handles may not be at the ideal placement because of your height, which would mean you'd have to stand farther back from the door, at which point the exercise may turn into more of a triceps kickbacks instead of pushdowns. To fix this, just grab the resistance tubing on it's own at the point where the band is just becoming taught with your elbows at slightly less than a 90 degree angle. Now pull the band down until your arms are straight and slowly return to having your elbows at a 90 degree angle, and then repeat until you can't complete a full repetition with good form.
This exercise is very effective with resistance bands. If you've done this exercise before with a cable machine at a gym, then you'll notice it feels slightly different with resistance bands. This is because with elastic tubing, you can't generate momentum, in fact, the exercise will get harder the more your stretch the elastic band. You can do this exercise very quickly using elastic bands and you won't be able to cheat. With a cable weight machine, you can generate momentum, which will make it easier for the last part of the extension, which is not ideal. On a cable machine you have to do the exercise at a slow pace to avoid this, but with resistance bands, you can go fast and hard.
Just remember, this exercise can't be done without a door anchor, so be sure to check out this exercise bands review and get a set that includes one.