In no particular order, here are some quick and cheap fortification ideas.
Domino walls
Buy cheap dominoes. You’ll need the boxes as well as the dominoes.

Carve/scrape some stone-like surfaces to the dominoes and glue them down onto the boxes …

Chop some dominoes in half to make the crenelations ….

Foam board glued behind …

Cheap gesso paint slapped on (if thick this adds texture) …


Paint, washing and perhaps dry-brushing …


Small artillery fort (emplacement)
Buy cheap wooden box …

Flip the lid and carve crenelations. Score stone-block effect on soft wood.

Make foam board earthworks base …

Plasticine, coated in glue …

Paint, stormpole/palisade, sprinkle some sand while wet …

Add gessoed and painted stone tower …


Gabions
Buy cheap pound shop cooking mesh and cheap fish tank gravel…


Cut the mesh …

Sew into shape …


Base and pour in some gravel …

Small artillery fort
Eat your gift biscuits or cake, save the tin (Or, if you are me, save almost everything) …

Tape up the tin so that you can apply gesso and paint easier …

Gesso …

Paint …


Wall towersÂ
Cheap boxes of appropriate shapes are scored to look like stone blocks …




Thinner gesso applied, then painted …


BTW, if you build anything, build the battered versions too (!) …


More ‘before’ and ‘after’ collapses to follow soon – just need to dig them out and photo them!