How do I make my self take daily showers in winter?

I keep my bathroom very warm, and I warm the fresh clothes on the heated towel rack before the shower so they are a pleasure to put on.

And if it is just too cold, I take a sponge bath snd count that.

If you can turn the heating up a little, make sure your home is warm before hand and put the towel on the radiator if possible. If not, its ok. My main motivation is remembering how I feel once I'm washed of and clean. Even the first few minutes can feel like a huge effort but its kinda OK once started.

And if you have any songs that you love to sing along too, play them! Songs that make you feel happy.

Daily showers are only needed when one works a job that gets them grimy or when one sweats often. Otherwise showering three times a week is sufficient and better for your hair. Shampooing often can dry out your hair. The natural oils in your scalp help keep your hair shiny and healthy. Using dry shampoo helps if your hair tends to get greasy after a day.

I have found that I need to take time for showers. Sometimes, I do take too long in them, but if I took them everyday (instead of every other) I would not feel like I needed to take longer showers at other times to make up for the missed relaxation time. Showers in the winter would also help me stay warm when it is cold. Whenever I do not feel like taking a shower in the winter, I can remind myself that the shower will be like a heater. I do not have to spend forever in the shower, and I will be able to stay warm.

I know it's a stupid response but simply forcing yourself to get up. No matter what time. Before work, after work, the middle of the night, just make sure you get in the shower before it strikes 12

Do you actually need to shower daily, or just think you should? If you aren't sweating or exposing yourself to potentially harmful chemicals or visibly dirty, you don't need to shower daily. You can shower every other day, even every third day if you really aren't working up a sweat and wear clean clothes each day. Our skin is happy to go a day or two at a time without a shower.
If you are concerned about odor, a quick washcloth bath, getting your private areas and arm pits should be ok.
As for how to stick to a routine, have a great playlist for shower time, or invest in a robe that feels heavenly. Shower at night instead or morning or vice versa. Whatever makes it fun and easy.