I’ve had a few questions recently from New sewers asking for tips on sewing straight lines. Whilst this really will come with time and practise, I recently taught some students a little trick with post it notes!
Line up the edge of the post it with your desired seam allowance groove when sewing seams. Then when you’re done, it’s easily removed and doesn’t leave a sticky residue. Most of us have post it notes lying about too.
For overcasting with a zig zag line up the post it with the needle when it’s in the right hand side of the zig zag.
Happy Stitching :)