Staying slim and healthy is key. Yes it does get tougher and more high maintenance when you get older. I’m 40 but have started doing a few things.
Cut down on alcohol. I still drink but less.
Drink more water. I have a litre bottle that I keep on my desk. Drink one throughout the morning and one throughout the afternoon. Topped up with herbal tea.
Cut back on caffeine. I have one cup of coffee in the morning but then switch to water and herbal tea.
Good sleep hygiene, 7-8 hours sleep per night.
Minimal but high quality skin care regime. Including retinol. Retinol hand cream at night.
Teeth - clean and polish every 6 months and whitening every few years.
Eyebrows - not a caterpillar but thicker makes you look younger. Get them professionally threaded and dyed. Colour in with pencil.
Try to exercise outdoors, if you can. A short run or hike gets the blood flowing anyway but seems to be even better when combined with fresh air.
As others have said - get your make up professionally done and see what suits you. I always find that investing in good quality moisturiser, primer and foundation works best and then scrimp on the mascara / eyeshadow (hello maybelline).
Buy some expensive, we’ll cut classic outfits and then bring them up to date with bits from Zara/H&M/Mango each year.
Hair gets dryer as you get older. Lots of conditioner and serum (I also have wavy hair). Mine is a bit longer but I still think the curls age me, so I straighten it but not so it’s dead straight. Maybe a few golden highlights throughout your parting? Less harsh next to your face.
Whatever you do, don’t listen to my mother, who thinks that it should be mandatory for all women to cut their hair off on their 40th birthday and go for the “I’ve given up on my appearance look”. She phoned me on my birthday to tell me this. She also suggested that I buy a Honda Jazz, should stop wearing mini skirts and ripped jeans 
. Then when she saw me, told me off because my bag didn’t match my shoes.