I am experimenting a bit with hairpin lace.
Finding inspiration at this board at Pinterest
And I found another board at Pinterest…..
With a huge loom I could make a combination of hairpin lace and sprang.

Photo 1: Several forms joined together
Photo 2: Making a circle
Photo 3: Using a different colored temporary thread to hold the loops
Photo 4: In the form of heart
Photo 5: Puff stitches
Photo 6: Crocheting around
Photo 7: Finished forms with puff stitches
photo 8: Butterfly
Photo 9: Different butterflies
Photo 10: Tree stitch
Photo 11: Working left hand loops
Photo 12: Continued at other site
Photo 13: Top of the braid
Photo 14: Finished braid
Photo 15: Crocheting half of the loops together - all loops twisted or untwisted at hook, yarn over, pull through, ch 1 to secure
Photo 16: Combined with knitting
Photo 17: Adding knitting at one site
Photo 18: Starting Tunisian crochet at the other site
Photo 19: Tunisian crochet
Photo 20: Working at a huge loom - combination with sprang
Photo 21: With sprang and crocheting
Photo 22: Combination with sprang and knitting
Photo 23: Combination with sprang, knitting, crocheting and weaving
Photo 24: Using different material: satin ribbon
Photo 25: Using a cord made at a lucet
Photo 26: Finished leaf, made with lucet cord
Photo 27: First experiments
Photo 28: Working in a special loom off center
Photo 29: Combination with broomstick lace crochet
Photo 30: When you make longer strips it is advisable to pull a different colored thread through the loops before taking the loops of the loom

I will describe now some of my experiments.

Making a circle
Distance between both legs of the loom 4,5 cm.
Crochet hook 3 mm.
Make a basic strip with 40 loops at each side, bind off and weave in the ends.
Pull yarn twice through all the untwisted loops at one side of the strip, pull firmly together, make a knot and weave in the ends. Sew also both ends of the middle of the strip together. Crochet around the circle, this time using the twisted loops: sc 1, ch 1 in each twisted loop all around. Close the circle with a slipstitch. Weave in ends.

Making a heart
Distance between both legs of the loom: 5,4 cm.
Crochet hook 3 mm.
Pattern in the middle: sc, hdc, dc
Using the pattern above, make a strip of 15 loops at each side. Take the work from the loom, but keep the hook in the work.
Ch 3, take all the loops from the left side at the hook (untwisted), yarn over and pull through all the loops, ch 1 to secure, ch 3, sc in first stitch of the middle stitches, ch 3. The rest of the loops will be worked twisted: sc 1, ch 3 in each of the twisted loops, till the end. Slipstitch in the last stitch of the strip. Weave in ends.

Making a braid using puff stitches
Distance between both legs of the loom, 2,5 cm. For the first stitch I made it a bit more narrow.
Pattern in the middle: puff stitches, according to this tutorial:
https://www.youtube.com/watch?v=r7BVgfbzQQ0
Using the pattern above make a strip as long as you like.
Bind off and weave in ends.
Crocheting around the form (with a different color): 
At the sides sc 3 in each bow of ch 3, sc 1 in each twisted loop. At the corners you just make as much as single crochet stitches as you need to get a nice round corner.
I made 3 of these braids and joined them together, using chain stitches, single crochet stitches and sometimes crab stitches.

Butterfly
I have tried to make a butterfly also, but I was so much freeforming with it, that it took me 4 butterflies to write a pattern. However here is the pattern of one of the multicolored butterflies.

Pattern used in the middle: sc, hdc, dc.
Distance between both legs of the loom 5, 4 cm.
Using the pattern above, make 12 loops at each side.

Ch 3, take all of the loops of the left side twisted at the hook, yarn over and pull through all the loops, ch 1 to secure. Ch 3, sc in first sc in the middle part of the braid, ch 3.
Continue working {sc 1, ch 1, sc 1 in twisted loop} 2 times, sc 1 in next twisted loop, sc 1 in stitch under the same loop, to get the wings, repeat from 3 more times, make slipstitches in the next chain 3 space till the middle of the butterfly, chain 12, pull this chain around the center of the butterfly and attach at the top with a slipstitch.

Making a braid using tree stitch
Distance between both legs of the loom: 3,5 cm.
Pattern in the middle: Each time after the turn first make a slipstitch and then a tree stitch. The tree stitch you make this way: (pull up a loop, yo) 3 times, pull through all 6 stitches. You have to work quite loose to get a nice stitch and to be able to pull through.
Using this pattern, I made 36 loops at each side.

Then I took the loops of the right side at a very large stitch holder (you can also use a different colored thread for this) and started working at the left side:
ch 3, {sc 1 in back of loop (you get a twisted stitch), ch 1} repeat till last stitch,
sc 1, treestitch at the corner, ch 3, continue at the other side as before. At the end I added a tree stitch, ch 1, tree stitch, ch 3, dc, because of the form at the end I wanted. But you can do this as you wish.

Note: Of course you can experiment a bit further with all of this -changing the size of the loom, the number of loops and stitches and the yarn, will give you a different result. Just try and see what works best for you.

It is also possible to combine hairpin lace with knitting or with Tunesian crochet.