Any hacks that actually make you sit down at a particular time to work?

String habits together. If you already have a habit of having a morning coffee, associate that habit with starting work.

Mustering up the willpower and discipline is hard.

When my brain is complaining, I overcome it by completing one step at a time:

me: we need to go to the gym
brain: im tired!
me: just put on one gym shoe
brain: hmmm okay
me: now put on the other shoe....take one step out the door...
brain: wait a second...
me: keys in the car.....hit the gas pedal....halfway there...

and before you know it, youre at the gym and your brain hates you but youre snickering cuz you tricked it

Checkout Tiny habits by BJ Fogg Ted Talk. You will become a BJ Fogg promoter just like me.

You should try using some kind of app to figure out what your main distraction is. For example, you can use Worktime https://www.worktime.com/ if you use your computer all day and you're tracking which programs you 're using all day.
You can make use of this data and then try something like the pomodoro technique https:/www.wikiwand.com/en/Pomodoro Technique to indulge in your guilty pleasures, but only for a short time, and then get back to business. It worked for me. This method is going to help you get those natural breaks that Richardchu mentioned.

I find it helpful to work less.

When you're working at home, you don't get the natural breaks that you might get while in an office. So scheduling breaks/walks often and quitting work at a certain time (with no exceptions) is a good way to make sure that you're actually working.

Work also tends to fill the time available to it, so if you have less hours dedicated to working, you will naturally finish faster.

Schedule your day. Every task that is 15 minutes or more just schedule it. I have my coffee time in the morning and then a reminder tells me "Write Blog at 8AM" is next. When you don't have to think about what to do next, it makes it 10x easier to do it.