21, HELP!

So my boyfriend turns 21 in June and I have absolutely no idea what to get him. I've thought of everything from a couple of nights away to a new watch, 21 silly things that mean somethings to the two of us and I still have no idea what to get! Please help a girl out!! 
We've been going out for almost a year so I don't want to get something too little, yet, I don't want to get something too small either. He's quite sentimental and appreciates everything! 
Any suggestions would be much appreciated!☺️