As a keen 3D Printing enthusiast, nearly all of my projects have 3D printed parts. At home I use my personal Geeetech A10M, which is an Ender 3 replica with dual extrusion and a mixer nozzle, which allows for gradients throughout models. At school I use a Formlabs Form 2 and 3 for high-detail parts, and a Creality CR10 for large parts. I don't have access to any SLS or MLS facilities so if I needed sintered parts I would outsource them.
I use 3D printing in my larger projects and also for small around-the-house improvements and repairs. Using Fusion 360 for all my 3D CAD is very quick and has allowed me to complete many 1-day or few-hour projects including wall planters, storage hooks for an IKEA modular system and small toys and gimmicks as gifts for friends. 3D printing is a brilliant method for iterative design too, as it allows for the creation of multiple iterations within a day; this has been very useful for my EDITH project where I needed to design a hinge to go around an existing glasses frame, and a Nerf SCAR rifling barrel for which I needed to precisely adjust tolerances to balance drag and spin.
As well as a tool for idea creation, 3D printing has itself become a hobby for me. With printer upgrades and repairs, filament tuning and testing the strength of different print-orientations, there are so many aspects to explore within the 3D printing hobby. I often use Thingiverse to find test-prints and fun things to make without having to design them myself; and you can check out my own collections here.
Note: I am currently having heating issues with my 3D printer, where the printer will start heating to 190℃ but stop at 80 before giving a "heating failed" error. I have tried replacing the thermistor and re-building the hot-end to no avail. If anyone has a solution for me please get in touch!