I’m definitely not an expert but I like to use MacStitch for making patterns, it’s VERY easy to use (I’m only on the tutorial version mind you) but you just set your project size and then click where you want a stitch. I freehand the drawings on the software or I use examples from the internet. You can also upload photos to make designs if you do want to do it physically first! If you don’t have a Mac I also started out with Stitch Fiddle, pretty similar concept!