Hi, I'm pretty new here :)
I've played violin for about 3 years, and I play with a youth orchestra. Lately I have noticed that I am terrible at sight reading... whether it's a new piece for orchestra or the next song for lessons, I can't seem to get very far at all without hearing what it sounds like.
I think it's a problem with the rythyms mostly? Between looking ahead, getting the notes, etc. I find it really hard to count/subdivide and it's a mess.
How did you guys get better at sight reading?
I think you're right on the money with the rhythms. I always feel reading rhythms well makes sight reading much easier, much like hearing rhythms well makes transcription vastly easier. Many people focus so strongly on the pitches and may not realize how important the rhythmic factor is. If you can identify longer rhythm passages at one glance, you've gotten it out of the way and can devote more attention to the pitches. Additionally, you will recognize that rhythm passage faster if it occurs again, whether or not it has the same pitches as before.
There are two rhythmic exercise books called 150 original exercises and 127 original exercises. IIRC they deal with rhythm almost exclusively.
I find the Rhythm Sight Reading Trainer iOS app to be very helpful. Learn to tap the rhythms.
This article may give you some guidelines:
I've incorporated both volumes of the "I Can Read Music" books into my curriculum. One advantage is the duets in the second volume, which give practice not only in learning rhythms but in practicing the principles of chamber music and listening.