Are you looking to experiment alone or with your partner? He/She might well be up for some experimentation too so if you haven’t broached the subject then perhaps you should.
For me sex “feeling good” is both about the physical and the mental. A good vibrator / dildo combination (I swear by my rampant rabbit) is great for solo work! That stimulates the purely physical and is good for some quick stress relief. I am far more inventive with a partner and the rabbit stays in the drawer!
Things lots of people like are: kissing, massage, touching (your standard erogenous zones), cunnilingus, him using a vibrator / dildo / wand on you, different positions...
Things that can help get you in the mood: lingerie/outfits, lighting, lube lube and more lube, sexy talk or texts before hand, sexy talk during.
If you want to get a bit more adventurous there is light bondage (someone gets tied up), light spanking (hand on bum is a good place to start), anal (I’m a newly converted fan!), role play, taking pictures / video, sharing fantasies.
If you find any of that works for you you can take it heaps further if your partner wants to but you need to read up as BDSM can be dangerous without some safety precautions!