Blending?

I'm currently mixing a duet that I'm doing with a friend of mine and I would really like to know how to make us blend better (and for future mixing, of course). I know timing and volumes are key parts of blending and reverb helps a lot, but is there anything else (like maybe effects? I use Sonar, if that helps any) that might help?

Btw, I've seen the beginner's guide to mixing thread but it can only help so much...

Amplitude And Compression > Dynamics Processing > Classic Softknee
- This is a big yes. What this does, and I have no idea how this works, but it levels out vocals, and even if you have one vocal at 30dB and one at 3dB, it can make it so it meets right in the middle, or at least close. I recommend this for your cases, and for groups.

What I typically do is the following [Please keep in mind that I use Audacity]
- Move the vocals along so they fit with the beat. You have to be very careful with this because it can affect the final product completely. It must be perfectly on time.
- Compression tool. Click to the side and then go to Effects -> Compression. Click "Ok" and all of the lines should then highlight and compress.
- Equalization. Do as before but go to Effects -> Equalization. Click "Even line" or something along those lines so that the line is completely straight. Press enter and this adds some EQ.
- After effects. Once you've done the above, you can add effects and add what you like.

Notes to keep in mind
- Make sure that you have everything you need before you do the above steps. If you continue to do each step after every line or take the quality will become quite bad and it can ruin the song.
- Add effects after you have done the above.
- You may still have to turn the instrumental down by 2 - 4 volume levels.
- Same for hamonies. You may have to turn those down a few levels, also.

Hope that helps.