Man there are plenty of ways of unstiffening your joints, you need a lil rhythm and a lot of soul Naw JK, that is always my complaint "a lot of folks make stiff sounding beats" I hear it all of the time no matter how dope, to me the element of stiffness is overlooked in a lot of producers works which sort of astounds me because a lot of times there is no soul added or personality to the track, I mean a little of yourself added into the beat is what I am saying is what you need and in many ways thats the difference between a masterpiece and just your average jo track or ok production...add some bounce and a little energy.
Fruity loops is not the culprit though....
There is nothing worse than a well orchestrated joint fully composed masquerading as hip hop and it has absolutely no feel or life or it sounds like a keyboard demo song LOL this is something that in many ways can be taught but in some ways it won't happen by luck, you have to inject a little bit of musicianship and apply basic concepts common to all music....you can use dynamics, forte's, mezzoforte, pianissimos and use different velocities...tones have different signatures and voicings so since music is an expression so if you want to express a feeling or point in your music you have to apply a lot of different things from the above than just pull out the sequencer and go....
This is a good reason why using samples and vinyl(backbone of hip hop btw) made by musicians do the work for you and assist you in constructing a dope track in a lot of case, if the loop is natural and prebuilt on its own befor adding drums how can you mess that up???? LOL arrange or add your pieces but a good sample has all of the ingredients if left alone shouldnt come across as stiff unless you not looping correctly....some might disagree but thats a big part of sampling, if you compose and play then you have to do that to each of the instruments you put into the sequence and mimic the instrument, it's behavior and how a musician that has mastered that particular instrument might play.
If you can't do that then try all of the above or just start finding samples and riffs that convey the feeling....if the stiffness is in your drum track(the drum track in my opinion is what give the whole track the right feel for head nod factor if you not a good drum programmer you can get better but it does involve some practice and listening to breaks and drummers) but if you want to try and work on your programming then you might use a variation of an unquantized 4 bar sequence you do by hand using your click track or metronome and get it sounding hot then copy and paste and move things around to make the track seem varied, also for pianos and such I never use quantize......anyhow thats just some of my advice and observations.....