There's lots of times in quilting that you will have to sew 2 strips of fabric together with a bias seam. These seams are much less bulky and are hidden much better than straight seams. And luckily they are very easy to make.
1. Cut your strips whatever size you need. For this project I am making 6.5" strips for borders on a quilt. Trim off your selvages.
2. Layout 1 strip, right side up with the short edge on the right side and the rest of the strip going towards the left.
3. Take your second strip and place it right side down perpendicular with the short side lines up with the top and right edge of the bottom strip.
4. I know I try to never ever have to draw a sewing line on the fabric, but with a strip this large it is unavoidable. However with a thinner strip you can use your 1/4" tape line to get the diagonal line to sew on. I like to pin the top and right side of the strips so nothing slips.
5. Put a tiny mark on the top strip where the bottom right part of the bottom strip is. Now draw a line from the top left corner of the top piece to tiny mark you just made. This is your sewing line. I used a dark pen for you to see it, but I usually use one of the blue marking pen that goes away in water.
6. Sew along that line. When you are done unpin and open the seam up to make sure the sides match up.
7. Trim the excess off 1/4" away from the seam.
8. Press the seams open for less bulk and there you go. If you are making a longer piece (such as for binding) keep adding strips in the same way. The bottom strip will be the part you just sewed on and the top strip will be the new one you are adding.
Here's a quick tutorial on how to make a 36 patch that is used in the Twist Along With Sha QAL.
1. Decide on your layout. 6 rows of 6 squares. All the squares have to be the same size.
2. Now sew the rows together using a 1/4" seam allowance. Make sure the top and bottom of the squares match up.
3. Press the rows in opposite directions. Rows 1, 3 and 5 press towards the left and 2, 4 and 6 towards the right. This is when looking at the rows.
4. Sew row 1 to row 2. Make sure to butt the seams against each other so they fit together. The picture on the left is of a seam that didn't fit together correctly and the pic on the right is the correct way it should look. I find it best to pin the seam and flip it over to make sure they match.
5. Continue adding rows until all the rows are sewn together. Press these seams open. You will be glad that you did when we start cutting the twister blocks later.
Here's what my 36 patch looks like.