Drum kits carry the bounce.
Drums are the fastest way to define a beat. A strong drum kit should give you different shades of impact: heavy 808s, clean kicks, dry claps, sharp snares, tight hi-hats, open hats, percs, cymbals, and transition FX.
One-shots are playable building blocks.
One-shots are individual sounds you can load into FL Studio and play your own melodies with. Keys, bells, pads, leads, basses, strings, and phrases help you write from scratch while keeping a consistent sound palette.
Loops are for speed and direction.
Loops help you catch a vibe quickly. The best ones include tempo, key, and enough space for drums and vocals. They should inspire a beat without crowding the whole track.
MIDI gives you control.
MIDI files are editable note patterns. They are valuable because you can change the instrument, key, chords, rhythm, and arrangement while keeping the musical idea.
Presets help you finish faster.
Mixer and instrument presets are about speed. Use them as a starting point, then adjust to the track. A few tasteful presets can save more time than hundreds of random sounds.