This is a bit of a no-brainer, but when it comes to putting together a pocket page that will sit next to a layout i find it's best to use coordinating products so that everything looks cohesive. In my experience the two pages feel much more balanced if you scrap them together at the same time. Plus if you have to come back later to do the pocket page, chances are it won't get done! Whilst you're making your layout, have an idea of what you want to include in your pocket page and how it will come together. Be prepared to move stuff around, i have even re-printed photos in a different size in order to make a pocket page work.
The next tip is to do with embellishments. i try not to use bulky embellishments in my pockets, but sometimes i can't pass up the perfect flair or wood veneer! To avoid stretching the plastic i put the embellishment on the outside of the pocket. Just be sure to use some strong adhesive.
Think about what else you can include in your pockets to help tell the bigger picture. Receipts, tickets, maps, coins, business cards, packaging, quotes, snippets of artwork, weather reports, greeting cards, snapshots from your social media...the list goes on. If it doesn't fit in one pocket, no worries. Fold it up and pin in to place with a paperclip. Or cut it up and spread over two or more pockets.
i hope this gave you a new idea for your pocket pages.