Think about what kind of enclosure you’d like to use for your synth.
There are lots of options! I really like finding old speakers and building the synth circuits right into the speaker boxes/cabinets. One advantage of repurposing a speaker is it will generally sound good because most speakers have been designed to have good frequency response. Of course, if you are using an output jack to connect to an amplifier or a mixer, you don’t need to worry about your synth’s acoustics.
3D printed enclosures
laser cut enclosures
A thorough tutorial on making enclosures using a laser cutter.
2×4 enclosure using CNC machine
Here is a tutorial on making these simple enclosures
guitar pedal boxes work well too!
More helpful links