My giveaway of Geneviève Crabe's Tangle Organizer and Journal 2012 ended last night, but you'll still be seeing the pages as I come up with new tangles!
You will find similar patterns to Tricorn. Mostly, I came up with this to show two things--
One: if you find it difficult to judge where your next lines should go, you can always use dots first so that your eye will have a guide.
Two: Repetition of a shape is always a good method for coming up with a pattern. Mirror the shape. Turn it on it's side. Nest the repetition within the shape itself. I used a triangle, but this would work for other shapes as well.