Do you sew alot of half square triangles? You know, where you draw a line diagonally across a square as a sewing line and attach this square to the left or right side of a bigger square or rectangle? If you own a sewing machine with a laser in it, here's a quick way to sew these squares without drawing a line!!

Place your smaller square on the left or right side of your bigger square or rectangle. In this case, I am sewing a smaller square on to the left and right sides of a rectangle to make a section of a star block. Can you see the red laser beam on the green square? If you keep the laser beam so that it is lined up with the corner of the top square and your needle is in the same position (center) as the laser beam, you just sew along until you reach the other end of the square. Isn't that easy!!
Notice that I have another square set all lined up to follow the first set? This is called chain piecing for those of you who didn't know exactly what that term meant.
You don't stop to cut threads between blocks but leave yourself a speck of room to be able to cut each section apart when you have finished.
Here's what a whole line of them look like all strung together. In this case, I am adding a small block to one side of the rectangle set. Notice that I have already added my corner half square triangle (red stripe) to the other side. Chain piecing really makes things move along a lot faster so why not give it a try!
You can see in the right picture that I also have some other pieces already complete and ready to sew the next step. The little flying geese in the top right (green on one side, red on the other) have a little intersection where the red and green triangles meet. When you are sewing this type of section to another, here's what you want to watch for.
Where all of the stitching intersects, it should be a quarter inch to the raw edge of the fabric. No matter what, you want to sew through that intersection or just above it (towards raw edge) to get a good point or to not cut off your point. Do you see what I mean in this picture on the left?
You also want to make sure everything is lined up before you stitch this seam. 
In this case in the picture of the right, I have a seam (front section) in the middle that I need to match up with the point of the white fabric (back section). Just flipping the fabric down a little bit to be sure it's lined up makes it easier to keep in place instead of lifting the top fabric up and away from the bottom fabric.
Just take your time stitching along the intersection and use a stiletto to hold the fabric in place up as close to the needle as you can. It really works better than using your fingers and some times if you've used a pin, when you pull that pin out, the fabric may move a bit. Practice using a stiletto and see if it works for you. It's clumsy feeling at first, but give it a few tries!
Keep sewing,
loreen