I am often asked a version of the question Where do you get your ideas? and it's usually a stumper because my answer is too long. Given license, I think all designers could wax poetic about their muses.

Practically speaking, though, one design element of crochet that fascinates me is stitch patterns. I always view them in terms of how best to show off their textures and utilize their structures. Some, like shell lace, have so many variations and are flattering in so many different yarns, that they are seen in everything from hats to afghans to sweaters.
The spike stitch is merely a single crochet placed 2 or more rows below your working row and drawn up to the height of a standard sc. A SP-2 would be a spike stitch worked 2 rows below, and a SP-4 would be one worked into the 4th row down from your working row (i.e., if you were on the 6th Row of your pattern and you were instructed to make a SP-4, you would work it into the stitch directly 4 rows below, in the 2nd Row.).
Fabric made from patterns of spike stitches is quite thick and stiff, as the spikes are worked all the way around 2 or more rows. As a result it is probably not the best stitch for a lightweight shawl or summer sweater. It is, however, well suited for household items such as pillow shams & hot pads, or accessories like purses and totes.
Spike stitches of various lengths can be used in combination with each other to create geometric patterns in your completed projects. When combined with stripes of alternating colors, the possible results are without limit. To show you what I mean, I have designed 2 patterns that use similar versions of spike stitch patterns, which yield dramatically different finished objects.
I invite you not only to use these patterns, but also to experiment with other tessellations and colors. The first pattern, for the pillow sham [1], can be altered for any size pillow by adjusting your gauge and/or the number of pattern repetitions. The second pattern, for an evening clutch [2], includes instructions for a quilted lining and shows an example made with the best yarns and notions (but it can always be dressed down). And at the very end is an example of a third project -- a simple tote with a paper bag bottom [3]... and I challenge you to figure it out for yourself (which should be easily accomplished if you create these other 2 projects).
Links:
[1] http://www.crochetme.com/Aug_Sept_2005/patt_spike_pillow.html
[2] http://www.crochetme.com/Aug_Sept_2005/patt_spike_clutch.html
[3] http://www.crochetme.com/Aug_Sept_2005/patt_design_challenge.html