I put my youngest to sleep first and then focus on helping my oldest get to sleep. We read a lot and cuddle. Sometimes it doesn't work and he just rests instead--lies there, looks at books, and yeah maybe watches a movie if it is that kind of day, haha.
If the weather is all right and you can get out, going outside a bit before nap time almost always helps us. In fact we are dealing with a few days of no nap because it is way too hot to go out lately. Or even if you had some free indoor play places nearby. Or I'm sure you could try just jumping and running around a lot in your house, haha. Just something a little different--more active--than his usual activities. Sometimes even activities that aren't super physical but are just more involved than how he usually plays work for us--like a big (relatively; don't overwhelm yourself, haha) art project or science experiment. And then some kind of calmer activity like reading, I guess. I feel like I am just rambling because my 3 year old hasn't been napping and I am hoping to give myself an idea too, heh.
We don't have a strict routine or anything but our days are usually similar and I think that helps. Mostly because my son has a hard time napping when his dad is home (always results in a change of schedule it seems).
And the more upset I get about the lack of napping, the less napping he seems to do. Not saying you freak out as much as I do, hahaha, but I'm just putting that out there.
I would just let the nap go if he is resisting that much; it's just not worth it.
I hope you find something that works for your family! I know it can be tough!