Soft, tapered foam ones - Hearos is a good brand
I drown out the annoying noises with noises that I expect. I'll put on those 10 hour YouTube videos of random sounds (rain, train rides, cafe chatter, etc) and make sure it's just loud enough to cover up any other sounds from outside. My brain gets used to the monotony of the video and I'm able to sleep soundly.
If you're worried about getting "addicted" to a certain sound, just change out the video every now and then and try a new one. I have a playlist of videos that I choose from.
Have you tried a white noise machine?
I have one and love it. It really helps. It isn't really possible to be "addicted" to it.
The brand is Homedics and it cost ~ $20
It's not that it's addicting so much as it actually works so you never want to sleep without it.
You can get a free white noise app on your phone.
My parents have air purifiers in every room and they help immensely.
White noise is the best. Or a fan or anything that makes a steady sound that covers small random noises.
I am an insomniac and it helps.