im my personal opinion that vocal in the sample should be used a lot more scarcely, if you could use a diff portion of that song without the vocals for the main part of the beat, maybe put the part with the vocal every other 8 bars. Also, sampling is a great thing but you should add your own flavor, do more then just add drums, throw some synths or even your own piano guitar riffs, whatever, even try eqing out the bass in your sample and making your own bass line...