Kate, this quilt is a huge learning curve for me too, and I am sure for many others out there. I avoided doing a TQS BOM because I was to busy, it was too advanced etc. etc. every excuse you can imagine
Eventually I realised that I could learn so much from this, so took the plunge. Having watched nearly all the TQS shows and listening to all the advice out there, I have found that starching my fabric, accuracy in cutting, sewing an accurate quarter inch seam allowance and infinite patience are essential.
I come from a dressmaking background where if a seam allowance strays a fraction of an inch it's not the end of the world. In patchwork accuracy is essential.
I am way behind with my BOM but and that means that I can benefit from the advice of others on the forum from their mistakes. I watched and watched all of Margo's tutorials and find her advice and experience priceless. She has made this quilt up twice already so knows any snags there are out there waiting waiting for us to come along.
Almost every technique I am using is pretty new to me. I may have done a sample in a class ten years ago and not used it since. You are obviously comfortable with applique. I found that a major challenge and found a nightmare. I had put too many hours of work into it to redo it all and start from scratch again, but I had learnt how to do the next applique pieces better. I then put on a crumbcatcher and applied my setting triangles, the piece then didn't sit flat and square. I hadn't starched the fabric and the bias edged had stretched. I took them off, used new fabric, heavily starched as adivsed and they went on well. Then I discovered that I had omitted to put the crumbcatchers back in. They had looked looked so good, but I decided not to risk my luck again so left it as it is.
Like you I want to be pleased with what I have done. However don't be too hard on yourself. Step back and look at the work. I know that the imperfection show less when seen at a distance and when the quilting is done. When I view my lattice blocks on the design wall what I see is the coloured of the lattice against the cream background rather than imperfect seam matching hitting me in the eye. On joining the lattice block I found that pinning the seams accurately was the one of most important things to do.
I know many others will have encouragement and advice to share with you too. I hope that you enjoy working on the rest of your quilt and that you can be pleased with what you have achieved.