Some more tips...
Clip curves to just before the paper. If you clip right into the paper then you will get pokies (little threads sticking out) but if you stop about 1mm to 2mm before the paper, the fabric will stretch as you press the fold and will make a nice smooth curve with no pokies.
If you need to press a long curve or a tight curve, a little bit of glue (ordinary glue stick glue) will help hold everything in place. Don't use it too much otherwise it's difficult to remove the paper later.
When topstitching a piece where four shapes meet, stop at the beginning of the seam allowance. If you sew the whole seam allowance down then you won't be able to fold it back... as I'm about to demonstrate.
Take the point at the tail end in the seam allowance and press it open.
Fold the seam back so now you have the tail tucked in and a neat angle to the seam.
Now the next piece can be positioned. Press the corner as precisely as possible. Line up the edges on the basting lines on the previous two pieces. This is easier if you have the corner facing you. Pin the corner. Flip the work over and make sure that the freezer paper is positioned correctly in line with the design on the stabiliser. Baste the unfolded edges. Flip the work over again and topstitch the folded edges.
That was an obtuse angle - easy to fold. Here is an acute angle. I press one side, unfold and then press the other side. That keeps the corner crisp and accurate. Then I fold both sides in at the point and use my origami skills (what origami skills!!) to fold the tail back and make a kite shape. You may have to click on this photo to see what I mean.
I used to try to trim the bulk out by cutting the point off but that just makes it difficult to turn under and leads to pokies. Leaving a 4mm to 5mm seam allowance all the way around works better.
When I get to the corner, I leave my needle in the work and turn the work around ready to come down the other side. The kite shape is in the way but because of the way it is folded, it pivots easily at the point. I take a pin and just poke it back under.
And there you go, ready to sew the second side. It will feel like there is a bump under this point but by the time you remove the stabiliser and freezer paper, this seam will be flat.
I've finished half of it already. This piece is 400mm by 300mm so some of the pieces are quite small. The feet are fused but the rest is done using the baste and topstitch method.