First, take the print square and a neutral square and place them right sides together.
Next, sew a quarter inch seam around the entire square.
Then, cut the square on the diagonal from corner to corner in both directions.
{I drew lines just for a visual; it's not necessary and just adds an extra step.
Just use a ruler as a guide when cutting}
Press each new smaller square open and there you go, 4 half square triangles!
{Square up each block if necessary. If you sew a perfect 1/4" seam there shouldn't be much to square}
Half square triangles are easy to do and the variations in design are endless! I hope this pictorial helps and please feel free to ask questions or leave other tips you find handy.
~alician