As with normal crochet, you can make lace with Tunisian crochet! It is actually the same technique as used in knitting. You make yarn overs!
It is very easy, and you could even grab a stitch dictionary, pick a lace pattern and use it to create a Tunisian lace pattern. Just use the Tunisian Knit Stitch and yarn overs!
The yarnovers are only made during a forward pass and after you made an item you should treat your work the same as lace knitted items. It really needs a blocking treatment to let the lace pattern shine.
How does it work?
Make a foundation row.
Start a forward pass.
On an indicated spot for an open space, make a yarn over and skip the vertical bar where you would normally make a stitch.
Work your forward pass as you would normally do.
On the return pass treat your yarn over as a loop.
Finish your row.
That's all there is to make Tunisian Lace! Here is a nice pattern to practice your yarnovers!