Should always pack for longer than you expect.
While what I pack will vary,
I tend to try to keep some essentials on my person, as opposed to having everything in my pack.
Small first aid kit (about the size of a pack of cigarettes stays on me.
For firestarter I used to carry drier lint,
I tried both lint and cotton balls, cotton balls does burn longer so have switched to cotton balls,
And keep 2 sets of matches and starter 1 on me and one in my pack.
Do carry more than 1 knife.
1 on me and one in my pack,
For water I try to bring along a hand pump filter,
Its smaller and lighter than carrying the water I would need for the day. No shortage of water where I hunt/hike.
I recommend people try their gear out before having to use it in an emergency.
Be surprised how the simplest things is not so easy when doing it for the first time