Very unoriginal, but I have come up with this little snow-capped mountain thing which ticks all the boxes for techniques that should be included. Started off with a jagged snowline, but I think the smooth curve will look better and sawing curves adds to the technical variation. We are allowed to use copper so I am doing that to save money and I am going to polish it to a matte finish rather than have it hyper shiny.
(the snow bit will be cut out so you would see whatever is behind it)
I also bought these cool sheets of coloured anodised aluminium which if they are good to work with could make some nice little Christmas decorations (the green would also be a good alternative for my mountain design):