They are great no just for warm up, but for developing finger independence as well.

These exercises are quite fun too! You might even consider dropping guitar and doing something like this:

Please notice that first two notes of every arpeggio are picked up, while the third one is picked down. Make sure NOT to sweep-pick those notes. The idea is to give the picking hand as much work out as possible, so we are not after the economy of motion here.

Here is the basic form of the exercise:

As you can see each finger is responsible for one fret. I start with the 1st fret only because the pattern is more obvious there (fret number corresponds to the finger number). It is advised to start playing the pattern higher on the neck (say 12th fret and then move down to the nut).

Below are some variations of the basic exercise. Play them all so that you ill not feel bored too quick!

First variation changes the order of the notes: we play from left to right when moving down and from right to left when moving up. The second variation shuffles things around even more. Thats great for the finger independence.

Feel free to come up with your own variations.

The word of advice: it is very important to play this particular exercise using metronome. Start slow and make sure each note is sounded well. Play with alternate picking.