Ideally, two different images will spark off one another and is some way there will be a relationship between them. At least, this is how I have interpreted everything that I have read on this!
Traditionally, haiku is written in three lines, with a 5-7-5 syllable structure.
There is often an emphasis on nature or the seasons but this is not a hard and fast rule.
So, here goes...
Dew drops held captive
Morning sun unforgiving
Weary man tilts hat
A fire breathes and chokes
Beautifully destructive
Waves on sandcastle
Fragments of time lost
Cool air still on mountain ledge
The circling begins
Whispers lost somewhere
Darkness descends over land
Fragile wings flutter