I use a L-Shaped gluing jig to hold the parts while I do the glue-up. Shown here I have "Blue Painter's Tape" on the jig, but it is much better to cover the surfaces of your jig with the clear, shiny Scotch package tape--stuff that the glue won't stick to.

This photo shows the gluing of only 3 sections--it is the sample I made for the class, but in reality we want to glue all the 9 segments shown in the previous photo. When doing the glue-up you want to squeeze the segments together so that you get a tight joint between Maple and Walnut parts.