How can I decorate a large pine cone?

Hi Mark, you can use spray glue or even just brush mod podge on a pine and then dip it or sprinkler it in glitter and jewels. If the jewels are very large hot glue might be a better option to hold the largest pieces better.

Brush on glue or mod podge and sprinkle or use rubber tipped tweezers to place your gems. When I do glitter projects I use a plastic tub or old shoe box. Keeps the glitter from flying all over the place. Set on parchment paper to dry.

A good craft glue would work well. You might even consider painting them a metallic color or white first to make the glitter and jewels really pop. Good luck!

You could also bleech them.

To keep the glitter from coming off. Glue then glitter, dry then seal again with PVA.