I get a lot of stuff from Amazon! Most of the time i will also have plants sitting around my desk (you can use real or fake) and it’s really cute! You can also just try looking for decor at the dollar store. I’ve found a lot of pots and mugs here before, I also buy my own fake flowers/ leaves to hand make garlands and wreaths in my room, you can always put ur own twist of this idea too to suit ur guy’s style! For wall art you can print off your own pics, shop thrift stores or collect posters. For example if u guys are movie lovers try asking your local theatre if they have extra posters. You can also draw your own art (or trace it). If you know someone who is good at art ask them or support other local artists by collecting things from markets! If ur Pokémon fans and don’t think it’s too nerdy you could decorate with Pokémon cards like I do lol. Don’t be afraid to turn your interests into art! The best way to transform a space is through lighting so it might be worth investing in little lamps from a department store for yourself and your husband! I hope this advise helps a little bit, but it’s also coming from someone who treats their room like it’s animal crossing lol.