Lack of rehearsal skills is an unfortunate, yet very common problem. You mentioned recording rehearsals, this is a wonderful tool for realizing your mistakes, as well as the nice spots. Here are a couple of tips that I find work best:
1. Sectionals- If the problem with the song is say, groove, there should be a time when the rhythm section works on the tune seperate from the rest of the band. If your band is a three piece and the gtr does rhythm and lead, then he does need to be there.
2. Isolation- When you know that the band is having a problem with a particular part of a song, just spend some time on that particular problem. If you are only having trouble with the ending, then why continue on the rest of the song, it just wastes time and is not that productive. Figure out the trouble spots, isolate them, fix them, and find the next trouble spot. Once those are fixed, then try the song top to bottom, you may need to go back and fix certain areas again.
3. The time factor- Many folks seem to think that constantly playing the tunes will fix all problems. There is probably some truth to that, however, I don't think it is the most productive way to go about rehearsing. I find that it usually wastes a lot of time.
4. Charts- if you can write charts(usually as individuals, because you'll find the drummer writes charts differently than the guitarists, bassist, etc) this helps a LOT. Not only will it give reference points that you can call at so that everyone understands where you are talking about(I.e. Second verse, bar 6), it will also help you all retain the music better, and therefore not need countless hours playing the same thing over and over!
5. Listening- Listen to the band as a whole, not just yourself. Drummers, vocalists, guitarist, doesn't matter, musicians of any instrument are equally guilty of not listening to the band as a whole(although drummers tend to hear the layers easier).
6. Metronome- If you are planning on going into the studio soon, plugging a metronome into the PA will help everyone's time(but they will ALL loathe every second of it!)
7. Communication- This is a sad problem. Many, many musician's don't know musical terms very well, many don't know them at all. If you all could make an effort to learn these terms, then you will have a much easier time communicating that you want the bridge to have a giant accellerando, but then make the verse go "a tempo", and on the ending you want there to be a slight ritard, and the last note should be a pianissimo fermata.
8. Arranging- This can be done in numerous ways. I'll assum the songs are written by one or 2 guys, and then arranged as a band, since this seems to be the most common. When they come into rhsl with a new song, play the basic format, you know intro, verse, chorus, etc, so you get an idea of what it sounds like. Next, think about how you can give the song direction. I find this normally means figuring out the intro, bridge(s), transitions, solos, and the ending. I could go in more depth, but I think that is a start for arranging.
I hope this helps some, but I'm sure it was somwhat of an overkill. oh well
