What ways can someone motivate themselves (working out, at jobs, or simply doing chores) when they don't feel like motivating themselves in the first place?

 First thing that comes to mind is adding music. In that spirit, you can listen to any fun podcasts and multitask learning into it.

It is easier if the tasks you need to are part of a project. For example, working out leading to a first pull up or quantified muscle gains with reduced body fat percentage. At job, think about how doing that project better, will get you a better project or promotion. In the case of chores, you can use the Seinfeld’s “dont break the chain” method where you tick mark everyday on the calendar and keep at it.

You can also use chunking. If you cant do the whole thing at once. If its folding laundry, do it in breaks and also think how good the end will be.