Using a capo will allow you to play all open chords while allowing you to stay in the key the song was written in. If you are a singer/songwriter you will find this especially useful because you can spend your time working on the song and less time figuring out chords.

Here is an open tuning chord progression in the key of C(open position, no capo). The chords are the I (one), IV (four), and V (five).

The I chord
C major;

E |~——–|———|———|———|———|
B |~—1—-|———|———|———|———|
G |~——–|———|———|———|———|
D |~——–|—-2—-|———|———|———|
A |~——–|———|—-3—-|———|———|
E |~——–|———|———|———|———|

The IV chord
F major;

E |~——–|———|———|———|———|
B |~—1—-|———|———|———|———|
G |~——–|—-2—-|———|———|———|
D |~——–|———|—-3—-|———|———|
A |~——–|———|———|———|———|
E |~——–|———|———|———|———|

The V chord
G major

E |~——–|———|—-3—-|———|———|
B |~——–|———|———|———|———|
G |~——–|———|———|———|———|
D |~——–|———|———|———|———|
A |~——–|—-1—-|———|———|———|
E |~——–|———|—-2—-|———|———|

Learn to play these three chords and you will be able to play a ton of songs out there. Change the tempo or the progression and you can create a whole new song.
Like anything there is a bit of a learning curve but stick with it and you will get there.