Here are some useful eleventh chord shapes shown in the first four frets. As with previous chord types, learn each shape and then transpose it to all keys.
When the notes of an 11th chord are picked separately, you can get a good effect by including the 3rd of the chord, as shown here. However, when all the notes are played together, the 3rd is usually omitted, or if the 3rd is essential, a sharp 11 degree is used.