Don't know anything about drum samples, but for presets/patches and synthloops:
Learn synthesis and techniques until it's in the back of your head, and practice until you can make sounds fast, making it all more profitable. Learn to make good music so you can make appealing demos where you show off your new products. Lastly, reach out to design companies and show your skills, or manage all your products and marketing by yourself.
Note that there's a lot of competition in this industry, so you need to put a lot of effort and time in evolving and getting great sounds.