I used to have trouble getting a decent length shower. I had to get up EARLY before dad left for work or wait until my son was napping to do it. Now I get nice, long showers every day by taking my son in with me.
When he was smaller, I put his little sitting-up bathtub at the end of my tub and filled it with water and toys. He got to play and splash while I showered. Now that he’s older, we keep a plastic tub filled with his bath toys in the shower. He loves to pour water in and out of his teapot, play with his boats, take the lids off empty shampoo bottles, and more. It’s good playtime AND I get to shave my legs! When I’m all done, we wash him off. Sometimes I put the plug in the drain and run a bath so he can continue to play while I get out, do my hair, and put on makeup. We recently got a shower head with an extra faucet so that he gets his own shower spray.
He loves it and runs eagerly to the bathroom if he hears the word "shower." When he’s getting out, he almost always says, "Mommy, nice shower!"
Disclaimer: This hack only works with kids who are old enough to sit or stand on their own. Also, since he is a boy and I am a girl, it will need some revision as he becomes more aware of bodies, body parts, and nudity. But for now, it’s working great!
Related: Bring the high chair in the bathroom