1 use some metal
2 use white, grey and a touch of another colour
3 heat embossing
K follow a step-by-step by Christelle here
I had an idea for card 2 so I started with that. Using only white and grey meant it had to involve snow so I used a KTZ snowman.
I stamped him in Brilliance starlite black (which is a soft grey) on scrap card, double embossed his scarf and cut him out. The background is some grey paper with a slight pattern. I stamped some snowflakes in Brilliance moonlight white and heat embossed them with clear glitter powder. I tore some white card to make some snowy ground and added a grey embossed sentiment. This was mounted onto a white card blank.