The floor tile and the shower unit look great.

If it were my house, I would tackle the vanity area. I would paint the cabinets and mirror frames white to match the ceiling beams. If it isn’t enough, you can always change the vanities And countertops later. In the meantime, a DIY paint job might be enough to overcome those distracting cabinets.

I would run chain and hand pendants from the ceilings, which was a big 70’s trend. Here are some light fixtures to consider:

4-Light Black and White Round Drum Shade Chrome Finish Pendant Chandelier Modern · More Info

Kira Home Elizabeth 22" 3-Light Modern Pendant Light, Warm Brass Accents + Black · More Info

Ohhhh. I love the second light! Thanks so much for your ideas! I like the idea of painting them white.

IMO nothing special about the 70s stlye so staying true to that era would be my last thought.IMO those cabinets are a good example of really awful design and color with that awesome ceiling . Bathrooms need good lighting just like kitchens IMO and not some chandelier bulbs that light nothing . I would gut that area and redesign the cabinets with no drop down area no cabinet sitting on the counter so nice simple high gloss cabinets with no framed mirrors good bar lighting that lights the area where you need to see. Unless you are planning new floors wou will need to make sure the new cabinets work with the tile for layout. I often use automotive paint to get a color that works for cabinets and that great gloss finish.

What is your budget? And where does that door on the left lead? For a larger budget, replace the tile, cabinetry/countertops, lighting, and mirrors, and paint. For smaller budget, put a filler piece on the bottom left cabinet (to resemble current cabinet door), paint cabinetry (the color of your trim/beams), replace light fixtures (center the one on the left), hang frameless round mirrors (center the one on the left), and paint a warm white.

When you say update, is it cosmetic only or did you want to change the vanity and its configuration? The rest could remain and I would restrain the ceiling to match the light wood tone in vanity You could also paint the sliding and interior door black so as to compliment shower door.

That corner piece is hulking over the whole room. Corner cabinetry is usually a wasteful use of space so I would remove that. You don't mention budget. Low = paint cabinets and find fun bar lighting. More, counters. If you can leave the sinks where they are and the floor, a facelift wouldn't be too pricey for new cabinets.