It's hard. My husband has been limited to 2000mg a day (I think, have to dig it out). Things he thought were safe (caesar salad

) aren't.
Not putting salt on things is a no-brainer. Reading the labels on things is key. You have to watch what you trade off for though. They make a salt-free ketchup (he prefers this to regular ketchup) but it is higher in potassium. This is bad because of one of the medications he is on, he needs to limit his potassium also.
I find that making things from scratch is key. Frozen vegetables are way better than canned, but fresh is best. Frozen peas are sneaky though. The doctor's asst told us if it came from a box or a can, it probably wasn't good for him. Basically anything processed.
Spaghetti sauce is high. Try telling my husband that he can only have 1/4 c. of sauce, no cheese and half a slice of garlic bread. It's easier just not to make it.
I did think I was doing great, making a pork roast and slicing it for sandwiches for him. Then I read that they "injected a sodium solution" into the pork. So when I thought he was under for the day, he was actually over because of the meat. Chicken & pork are big on this, beef I don't see it as much (if at all).
Have you sat down with a dietician? My neighbor is encouraging us to do this, I have no problem with it. Getting my husband to do it is another story. He needs to take ownership of it, if he doesn't then it's just me being an ogre telling him that he can't have any of the good things.
Also, look at your breads and peanut butter. They make a salt free peanut butter, not the tastiest of things. Aunt Millies makes a bread, whole grain I think it is, has the lowest amount of salt. I want to say their potato bread is low also.
All I can say is do it while you can before you have to. He is on four different pills and should be for the rest of his life. All this is because of a poor diet that was high in fats and salt. This was a choice he made willingly. This runs in his family and his own father passed away at 67.