Do you want tidying tips to feel calm and uncluttered when you walk in for whatever reason, or a relaxing product to use in the bath / shower that feels posh and spa-esque? Two very different requests OP!
For an overall tidy=calming vibe, agree with PP - good storage to keep the surfaces clear is the way forward, and bonus points if it’s got another purpose or uses up dead space, like those IKEA bamboo freestanding shelves that slot over the toilet, or a large hanging mirrored wall cabinet for all the bottles. Yes to a few plants (but not 70s spider plants!)
Depending on family needs, perhaps give each person a different colour box to store their bits which live out of sight when not in use. Move stuff that doesn’t get used frequently (massive collection of half-used medicines I’m looking at you 
) out to another room.
Another thing that looks good and doesn’t take any extra time is to roll towels instead of folding and stacking them. This is only worth it if your towels are not in a cupboard - mine are on an open shelf unit, and this makes them look way fancier 
Oh, and create a nice smell! Not a nasty air freshener spray but a scented candle (Aldi!) or a few drops of essential oil that will hang in the air and smell all spa-like. You can put a few drops of oil on the wall of the shower (high up enough so it won’t get washed away) so the steam acts as a diffuser.
Wow, I apparently got quite over-invested in sorting out your bathroom OP