Using only rhythm to inspire some melody or lyrics

Make up an interesting rhythm, sing a more expansive tune across it using longer notes and less words

Make up a very simple rhythm, sing a more melodic and intricate line across it

Make up a rhythmic hook with gaps, stops and starts. Sing in the gaps.

Record just a rhythm into your sequencer on any old sound with one finger. Loop it. Sing over it.

Make another one and put it after the first one. Loop them both. Sing over that, see what comes.

Try putting these different rhthms alongside each other, you may hear something in their new clashing rhthms which is almost the beginnings of a tune.

Loops - get some insane and not so insane drum loops and put them together without getting into the technicalities of what is going on, only as an aid to inspire melody and songwriting, not just creating more loops. Listen to the way the loops interact, sometimes badly, DON'T tidy them up and start programming...listen carefully to the way the loops interact, and more often than not there will be a random melody playing as the different loops interact. Perhaps this little melody will inspire you...who knows..