1. With an interesting incident
The bomb will explode in one minute.
This interesting incident hits you in the face straight away. Is there enough time to defuse it? Is there enough time to run away? You would have to read on. Unfortunately, my book doesn't have any bombs in it. Yet. I could rewrite the first chapter to include more bombs. Alternatively:
2. Be abstract
Bombs are a bit mainstream. What if it was an existential bomb?
Why is the bomb? What is its purpose? It might not really be there. Probably is, though.
Yes. This can only be the opening chapter to a very serious book. It will make you ponder and pretend to be better than it actually is. Lots of interesting things will happen in this book. Or will they? Maybe it's just best to start with -
3. A really long sentence
This is a good way to trick the reader into reading more than they intended to. By the time they finish the first sentence they'll be so far into the book they'll think they might as well finish it.
The bomb will explode in one minute, which reminds me of a story my old bomb disposal teacher told me, it was a very long story and he told it all in one breath, he said...
If the sentence looks like it's about to wind down, that's the time to break out a semi-colon; an under-used punctuation mark for people who fear full stops.
The whole business of first chapters is so hard that I skipped to the second and the third and the fourth. They're easier.