It can't hurt to learn one of the thumb/index, or four finger sweeping approaches. Personally I just use two fingers and I get very fast sweeps with it, it's just about getting a rhythm between strikes, hammer-ons, and rakes. Really once you get the feel for large arpeggios down they become very very easy to throw in to anything at any time.
The best way to get better is just practice. Just take them slow.
The two main patterns are major and minor. Here's an example, I'll throw in my right hand approach just for the sake of things.
I = Index
M = Middle
H = Hammer-On
P = Pull Off
R = Rake
Major
Code:
G|-------------11-14-11-------------||
D|----------12----------12----------||
A|-------12----------------12-------||
E|-10-14----------------------14-10-||
I H I M I H P R R R P Minor
Code:
G|-------------10-14-10-------------||
D|----------12----------12----------||
A|-------12----------------12-------||
E|-10-13----------------------13-10-||
I H I M I H P R R R P From there you can experiment with adding extensions, 7ths/6ths, and covering more octaves.
Remember that they don't always need to be played in full. Getting this approach to arpeggios down is just another way of moving around the neck. I find working through the arpeggios for different modes and scales is a great way to find interesting colours to add to your music.