Thanks for the comments I really like the idea of putting a denim covered base in the bottom - will try this tomorrow. Better find the glue gun! I am now eyeing up all t-shirts for their bag potential.
The piping was VERY easy and really makes the handle and top look more professional. It just adds one more step to the process. I now want to do piping on everything! I used the zipper foot attachment for my sewing machine so you can sew right hard up to the edge of the piping - I think piping would be much harder without this. I NEVER pin anything! (just unpick a lot....) For the handle I had the denim upper and spotty liner fabric pieces. I sewed the piping to the right side of the denim first on both edges then put the spotty part good side facing in over the piping and sewed all three layers together using those first stitching lines as a guide. If you sew right on those lines you get a really perfect finish when it is all turned back the right way. A picture would be better - I will try and take some when I make another. For the top of the bag you sew the piping right around the inner edge of the bag outer before you sew the bag liner part on, use the first line of sewing as a guide and it comes out great when all done. Good luck I hope that made some sense, it is hard describing what I did.