A few things you should always pack
Sewing kit: sewing kits are solid gold. Believe me when I say that. You should never travel or do anything without one. They are the type of thing that comes in handy when you least expect them, or if like me you happen to be five centimetres taller than the ideal type for the pants that fit you and you need to hem everything they come in handy whenever you buy new pants.
A ruler: so maybe this isn’t useful for everyone but in many ways I am a living breathing stationery store. A former room mate used to come into my room and ask for things like glue sticks, tape, envelopes and was never once disappointed except when he asked for a ruler. I should never have overlooked that fact that someone like me will inevitably need to draw a straight line at some point in time.
Watercolour paints and paper: yes that is what I mean by “someone like me”. Watercolours are invaluable and a cheap set makes for large amounts of joy. You never know when you will need to under take a watercolour based illustration project for your travel blog.
Bedding: it is easier to just have it with you when you get there already. It is not a bad idea to bring unfitted double sheets because they will fit on most types of beds.
Basic eats of some kind: great to have when your flight is really delayed and you don’t have time to go to a grocery store.