I think the back line is OK however the vocals need some work.

Here are several things that i do to try and make my life easy when doing vocals:

Headphone mix: try turning everything up/down a little bit or even using only one of the headphones (whilst being careful of feedback). You could try listening to your self dry (with out any reverb) in the phones mix. Cutting out all non essential instrument tracks out of the headphone mix is sometimes a helpful thing to do.

Monitoring: Listen to your selves through monitors (not headphones) when you are mixing. Headphones can make you sound more in tune than you really are (it is flattering in the short term but no good in the long term)

Composite tracks: If needs be, cut three main vocal track and make a composite of all the best bits (by punching in and bouncing bits of tracks). Double tracking can help here also.

Tighten up the harmonies: This just requires lots of practice and there is nothing that says they all have to be done in one take.

Hope this helps
S