A pocket altar is a small set of items kept in a tin or matchbox that can be used to construct an altar on the go. They can be really useful for practicing whilst away from home, like forest rituals and when on holiday.
salt - a fast food salt sachet is really convenient
a pentacle - this can be on a scrap of paper
a handkerchief - both aesthetic and practical
a vial of moonwater - I keep mine in an empty Vaseline tin
small shell - to represent water
piece of moss - to represent nature
sugar - a coffee shop sachet is again, really convenient
protection bottle - keeps me secure whilst im travelling
mini pad of post-it notes - for sigils
home-blend tea - I usually bring a small sachet of home-blended tea that I usually charge with intent.
acorns and other seeds or stones
I really hope this helps you guys to make your own pocket altars!