I'm long winded, so I'll spoiler my explanation out...
I started Little Busters! S1 after it finished airing (sub) and got hooked on the character's relationships. The key was that I actually WANTED to enjoy the anime, and so I held back judgement on any characters until at least their arc finished.
I couldn't wait to see what happened in Refrain after hearing how good it was, so I began playing through the VN. Because I had actually seen a lot of the scenes from the VN, I was able to fully animate the frames in the VN. I still used my imagination a bit, but I also got excited any time I recognized a scene, it added a new dimension for me.
I watched Refrain Anime season while playing through the Refrain arc, but finished the Anime before the VN. I got so wrapped up in Refrain, it was crazy, but the VN helped make each story more real, just as the anime helped flesh out a lot of parts as I read them.
The most important thing: finish the anime before the VN. I watched Refrain's sadder moments and bawled my eyes out, but when I read it, I remembered how sad I was earlier, plus how much more moving it was in the VN ANNNNNND the VN doesn't keep going while you are busy crying your manly tears. I had to rewatch a few parts because my eyes had too much water to read, and I wasn't done with the emotions, even after the episode ended.
In the VN? you can give yourself all the time in the world to collect yourself, but Faraway is still going to be playing, so the mood doesn't end, like it will with the Anime. I would not have felt much if I had been through the VN first, felt all that, then been" rushed" through the anime (at least in some spots)
but.....
Tl;DR:
1. I watched S1 first and made myself actually WANT to enjoy it. (It wasn't that hard)
2. I started the VN before Refrain came out and had fuller ideas of how the characters moved (instead of having a few poses in different landscapes)
3. I watched Refrain's anime and played through it "together" (watched it as it aired)
4.I finished the Anime before the VN. So I was able to pull back on my emotions from watching it and was given the full time to enjoy them.
And a small rant on why I'm glad the anime and VN are different, and I prefer the anime (in some respects)
The anime focuses on FRIENDSHIP, where the VN focuses on smutty loli smut smut ROMANCE.
I didn't come to Little Busters! to see panties, so I actually applaud the anime for focusing on friendship and putting the "supporting" girls' stories on equal planes, but below the OTP Riki x KyouskeRin.
Respond to any/all/none of it, I just wanted to get this off my chest since so many people dropped Little Busters, but I still found a huge fanbase while I was in Tokyo