Looking for a smart tailor to make flat sheets into fitting sheets

Hello friends!

Someone who can turn my bedsheets into fitted sheets by stitching corners and adding elastic, and can make advocate collars for me? I'm happy to explain exactly what I want, but need the tailor to be smart enough to understand and do a decent job.

These are for kids beds. It's a pain to stuff single size bedsheets under toddler mattresses, there's so much extra material! 😅

Any suggestions would be great!

Thanks