I did this buying and flipping websites a few years back. Turned 30k into 100k. Stressful as fuck. Not hard work. Just takes intelligence, balls, and knowing when to sell.
I would invest 33% of it building affiliate websites online.
I would invest 33% of it in Ashford Hospitality Trust Series E preferred stock.
I would invest 33% of it in the highest yield savings account.
By years end I imagined you'd be up atleast 3% on the savings account, 9% on the stocks, and a 10k investment into a few solid affiliate websites could easily reap up 20k. You wouldn't quite double your money but you might do even better.
About 12 years ago I decided I didn't want to live in the system. I started freelancing. Doing web design work for churches. Slowly I built other websites of my own after my dad encouraged me to. Then this turned into actual 6 figure businesses and I haven't looked back. It hasn't always been easy but by far it's the best thing I ever did with my life.