Trello Gold user guide
To use the additional stickers, go to the Menu on the right side of your board and select "Stickers". You can drag and drop any of the available stickers and upload your own stickers by clicking the + button in the “Custom stickers” section.
To upload your own custom background, go to the Menu on the right side of your board and select "Change background". Click the + button in the “Custom” section to upload your own image.
You can upload files up to 250MB. To attach files to cards, select a file via “Attach file…” on the back of the card, or drag and drop from your desktop. The 250MB is for individual files, not a total limit, so you can have multiple large files on a single card or board.
As a Gold user, you can enable up to 3 Power-Ups on any board you're a member of!
Additional Butler features and quota
Gold unlocks Butler's personal quota with 200 command runs per month pooled across all boards, and the Calendar and Due Date tabs become available.
Uploading custom emoji
To upload emoji, open the comment field on a card, click the menu button in the bottom right-hand corner, and select “Upload emoji”. You will then be able to upload and name your custom emoji.
To save a search, enter your search terms and operators, click “Save this search”, name your search and then click “Save”. Click “Back to saved searches” to view your saved searches. To execute a saved search, simply click it.
The billing page
You can see when your account will renew, update your credit card info, see billing history, and so on in the “Billing” section of your user profile. Just go to https://trello.com/your/billing to access it. If you signed up via credits, you can check when your credits expire and you can enter a credit card and sign up for a subscription. You can cancel Trello Gold via a link at the bottom of the billing page.