A common technique to create sounds is layering. This can be done with drums, synthesizers, real instruments, basically with everything you can think of. There are different methods how it can be done. One of them is to create multiple channels with the same midi data, but different sounds and route those channels to a bus.
You could have 3 different kickdrum samples, each in its own channel, while you put a hipass filter on the first channel, a bell eq on the second channel to filter out the low- and highend and put a lowpass on the third channel.
Now you already have a pretty unique kickdrum, mixed together with frequencies from different kickdrums. Of course you can also just use 2 different kicks or even more than 3.
This works pretty well with synthesizer sounds. If you have a synth sound which sounds pretty cool to you, but too thin somehow, just layer it with a fat sound and filter out, what you don't need. Putting different fx on each of the layer channels and/or slightly altering the midi data in one or more channels, can also produce great results. It will probably also be necessary to adjust the volume of the channels and not have them all at the same volume. Picking one channel as the main sound and adding the other layers with a lower volume will help you to add what was missing before. If you created automations, you will want to copy them to your layer channels as well, although it can also give unexpected and nice results, if you forget to do so.
Transposing a channel up or down an octave is also something worth to give a try. Panning the channels differently might also be something you want to try, unless you are going for a mono sound.
If you still have to edit your midi data a lot, you may prefer a technique, where you send the midi data to your layer channels instead of copying them, so you avoid the need to copy the changed midi data from your main channel to your layer channels after every change, saving you some time. This will not work, if you are planning to have small differences in your channels, so it is up to you to choose what will work best for you.
Have fun experimenting and hopefully you'll be able now to give your sounds a new touch, they didn't have before.