Here's a checklist I made from some points from both How To Make Your Band Sound Great and The Music Producer's Handbook that will take you through the steps needed to troubleshoot an arrangement either live or in the studio.
1. Do all the players in the band know their parts inside out? Is there a part that someone is unsure of?
2. Are all the players performing their parts the same way every time (assuming that you’re not recording some forms of jazz and blues where you want a different performance)? Any variation can lead to a section not gelling or not being tight.
3. Is the band playing dynamically? Does the music breath volume-wise? Does the verse have less intensity than a chorus or bridge?
4. Does the band lose its drive when playing with less intensity? Does it forget about attacks and releases when they play quieter?
5. Is everyone playing the song and section starts and stops the same? If not, ask every player, “How are you playing it?”
6. Does the band sound tight? Are the attacks and releases of phrases being played the same way by everyone? Are the builds, turnarounds and accents being played the same way by everyone? If not, ask every player, “How are you playing it?”
7. Is the band in tune? If not, make sure everyone uses the same tuner and tunes the same way.
8. Does the song have a groove? Is the rhythm section playing in the pocket? Is the drummer or bass player slightly wavering in tempo?
9. Is the tempo right for the song? Try it a bpm or two faster or slower and see if it feels better.
10. Are all vocals in the best range for the singers? Does the singer have trouble hitting all the notes? Does the singer sound comfortable singing and is the vocal sound right for the song?