You're not going to be into every single guy you go out with. When you're shopping for a dress or a pair of shoes, do you buy the first one (or pair) that you try on and then try to force yourself to like them? No, you know if you buy a dress or shoes you don't really like they'll end up sitting in the back of your closet, unworn, and you'll end up feeling silly for wasting your money.
Same with dating. You'll date some you like and you'll date some that leave you feeling "meh". Maybe try a second date with Mr. Meh, but if you aren't "feeling it", leave Mr. Meh at the store! And try dating someone else.
When you meet someone you really do like, you won't have to force yourself to like him, it will just happen.
I dated one Mr. Meh and after 3 dates, I stopped. It wasn't going to happen and I couldn't force it to. I've also made the mistake of trying to have a relationship with another Mr. Meh and of course that didn't work either.
Save yourself for someone you truly do click with. Trust me, Mr. Just Right will be worth the wait.
FYI, my best friend dated many Mr. Meh's for years, and was so frustrated! I told her that it was taking her longer to find Mr. Just Right because someone extra special was being planned for her. Sure enough, she found him, and they are married with a family. Good things are worth waiting for.