What is the most effective way to recover deleted data and to convert files?

It is really useful to have special tools that are helping to recover files and also to convert them to a proper format. I was using https://www.magicuneraser.com/press/how_to_convert_mbr_to_gpt.php which is a proper service, that provides all these tools. It is a really easy option if you want to make all the tools really effective and to recover your accidentally deleted files. 

To be honest, I didn't quite understand the question. If you are talking about recovering deleted files, nowadays with modern software you can do this without any problems. Like example check these https://onmac.net/best-data-recovery-software-for-mac/ 10 best data recovery applications for Mac OS.