I've tried to build up a bit of a routine and I find that really helps, I also don't like to spend lots of money so here are some budget-friendly things!
Some people might think this is overkill/too rigid, but find for myself it helps me to have more time in the long-run to do things I enjoy and to relax after work.
Every day things:
I've tried to build up a capsule wardrobe (mostly off Vinted!) of tones/colours that all go together, I plan my outfit for work the night before and always chuck some jewellery and perfume on too.
I do the same, quick make up routine: L'Oreal true match serum (it has changed my mornings, you can apply it with your hands and it gives a light coverage that lasts!), blush, brow pencil/gel, and pencil eyeliner/mascara - set with spray. I use instagram to find hairstyle videos, nothing fancy, 5-10 mins tops.
At the weekend (not every weekend):
Wax and tint my own eyebrows (I just cut up face wax strips and use men's beard dye!).
Paint my nails - I use the Sally Hansen Insta-Dri so I don't have to waste any time waiting for them to dry.
Make and freeze a batch of soup for work lunches for the following week.
I workout a few times a week at home in the morning from YouTube, so I find the workouts I want to do the weekend before and put them in my calendar.
These things make me feel confident, organised and put-together :)