I’m new to the Aseprite community as well as pixel art in general. I’m currently an art student working on my indie game and I was wondering, I use a lot of reference for my drawing so is there a way to place a sketch into aseprite as a reference layer so that i can pixelate it on top of my sketch?
Yes. Layer> New... > New Reference Later from File does exactly what you want. It adds a layer (which you can move to the bottom of the stack) with an image from another file on it, so you can pixel on top without down-scaling the original.