A helpful tip is creating a diaper changing station on each floor of the house! It doesn’t have to be elaborate - just some diapers, wipes, cream, and a changing mat. That way, you don't have to worry about running up and down the stairs every time your little one needs a change.
It's also useful to keep some baby powder and some form of entertainment, like a toy or two, on the station for some quick distractions! You could even keep a small basket of goodies - some nappy bags, some snacks (for you!) and perhaps a toy or two, which you can easily grab and take with you if you need to change diapers on the go.
Most importantly though, have something that distracts your little one from what's happening! Some babies will be too curious about what's going on and won't mind too much, but for others it can be a real sensory overload, so having something to focus on instead helps them stay calm (and also helps you!). A hanging toy, or perhaps some music playing nearby could do the trick!