What colour threads should I choose for quilting a whole-cloth quilt?
I audition threads in the same way that I audition fabrics - and make a colour story. I take the end usage and where the quilt is to live, as well as my personal colour preferences, into consideration (and also what I have a lot of in my thread drawer!).
Weight (thickness) of thread will make a big difference to the finished look so go heavier if you want bold, and finer if you want a more delicate finish (the higher the number the finer the thread). You can of course mix weights in different areas of the quilt to create more interest. For example a thicker thread in outline work and finer thread for background areas. I'd personally be using Bottomline in the bobbin and then a range of polyester or silk in the top. These fibres will give an attractive sheen and (hopefully) good tension as polyesteer and silk are more elastic than cotton.
The more colour/tonal contrast there is between the thread and the fabric the more any little wobbles will show - so think about this aspect too.
Even after you have chosen threads it's all still under consideration as you sew. Things look different once stitched, so keep assessing as you move forward. Step back often to see what you are actually getting, and do not just sew blindly on without really looking at your work. By doing this you will be able to see what is working well and what perhaps needs further consideration.
Add a good margin of fabric, wadding and backing around your design so you have something to hold on to as this will enable consistency and more accurate results towards the edges of the work. This 'waste' area is also good for practicing stitch designs before 'real' sewing, and for seeing how the threads look and perform on the actual quilt.
And after all that enjoy the process! Philippa :)