here's an easy way to sew zippers for the buttercup bag from made by rae pattern. this tutorial is for those of you who has sewn the buttercup bag before as its mainly only pictures and very few instructions (im so lazy to write a tutorial) so that it will be much easier to understand :)
first you will need to prepare the zipper. sew both ends with a small piece of rectangle fabric. cut 2 larger rectangle fabric and fold it into half and sew on top of the zipper.
next place that piece of sewn zipper gusset on top of the RIGHT side of the lining pieces and pin in place. sew the same process on the other side of the lining.
you will have something that looks like this :) i hope everything goes on well at this stage. hehe
fold the lining RIGHT sides together with the zipper gusset folded inside like in the picture above and pin in place. sew all around the lining.
now for the last bit, insert the lining piece into the outer fabric piece (that you have already sewn together and attach the strap) and fold in both lining and outer piece. topstitch it close all around the edge. this is a little bit tricky as the top of it will tend to be very thick (lining + interfacing+ outer fabric + interfacing + etc hehe). just go slow and everything will be done nicely :) . for this bag i slip stitch by hand :P