Here's an easy way to deal with Maj7 chords if you want to use an arpeggio:The first example is a regular F#m arpeggio across all strings. It combines both alternate and sweep-picking.The second example is the same shape with one more note added: D. This approach is very useful since we can use that arpeggio now over a Dmaj7 chord. Why? Because we have all four notes of that chord; root, third, fifth and major seventh or D, F#, A and C# respectively. Notice the use of slides for that extra note(first finger on the low notes and pinky on the high ones).One thing I have to say about Maj7 chords: always use the root as a passing tone because it just sounds terrible when it's the last note of a phrase!Well, I hope this shed some new light into your arpeggios 'cause it sure helped me!

See ya!