How to easily add music to iphone 4s?

I'm having a huge amount of trouble adding and deleting music from my iphone. I have an artist unchecked in my sync music area on itunes, and i have manually deleted all of their songs off of my iphone, and yet every time a plug my phone into my computer, they reappear on my phone! It is so frustrating! How do I make this stop? I also have a couple songs left on a cd that I wanted to put on my phone. And I have successfully added them to my itunes library, but I can't figure out how to get them onto my phone. I dragged them into my phone manually, as there's no option to check the artist off as there's with my other music. They then appear at the bottom, under "manually added songs" and yet they still aren't on my phone. Can anyone help me please?

Solution: don't use apple products. I had to sell my iPhone online because it had so many problems

I just set my itunes to manual, then just select and highlight the songs you want, copy and then on the iphone use edit-paste… Works slick.

Just adding to Markus,

You can connect your phone to iTunes.

After that tick manually manage music and videos

A warning will appear that music will be erased.

Now you can drag and drop music onto iphone.

Select songs and press delete for the songs that you don't want.

Ensure that music never syncs automatically in iTunes