For this purpose, try a good drum sample library like Drumkit From Hell or Superior Drummer. I use these for programming progressive rock/metal drums for music that I make and no one can tell it isn't a real drummer playing. They'll say something like "who is playing drums?".
Once you do this, you will have to get used to programming in Piano Roll if you haven't already. The step sequencer is just too limiting, and with the above mentioned libraries, you have to use Piano Roll anyway.
In Piano Roll you can take advantage of the above mentioned library's velocity sensitivity (ex. if you hit the snare soft, it doesn't simply drop in volume, it sounds just like a real snare that you hit soft).
If you go this route, open DFH or Superior Drummer and then drop some of FL Studio's pre-made drum loops into Piano Roll (not the loops that play when you click them, but the ones found under "scores"). This is for study purposes. Observe how the midi track looks in Piano Roll. You will see varying velocities and you will get an idea of where all of your voices are (kick, snare, hi-hats, etc.).
When you go to make your own beats, the more work you put into it the better it will sound. For instance, I start by programming a really basic idea of what I want, and it usually sounds fake. Then I tweak the velocities and add cymbal hits and fills. My goal when doing this is to make it sound like a real drummer. Also, if you really want it to sound real, don't simply program a 4 beat loop and repeat it. Put in the work to actually program every bit of the song (so that your drum "pattern" is the length of the song - paste it once and you're done). It may sound like an insurmountable task, but there are methods that make it go by faster.
It also helps a great deal if you have any experience actually playing drums. I've played drums off and on for years and I know some great drummers. So, when I program I have a good idea of what is possible and impossible to play. For instance, if you have 16th notes going on the hi hats and you don't stop them for a 16th note tom roll, then you've just programmed something only a four armed drummer could play - therefore it will sound fake.
Now, that is a rough outline of how to program drums that sound convincingly real. You may not care if your drums are conspicuously programmed - I don't usually, it really doesn't matter unless you're one of those guys who hangs out in a music store all day repeating the worn out phrase "drum machines ain't got no soul" - but those guys shouldn't be considered an authority of anything. Besides, human beings don't have souls either, so **** it.