Automate or create templates for tasks you find yourself repeating a lot. There’s no need to waste time creating something from scratch (even if it only takes a minute) when it’s something you’ve done before.
Use placeholder text and images in your design work to keep momentum rather than waiting for final assets to be ready. In the beginning phases it’s more important to keep moving and getting ideas out than it is for the content to be correct.
To speed up your workflow, you have to be okay with being scrappy. Don’t waste time worrying about being perfect.
Remember that there isn’t one correct workflow. Things that speed others process up may not gel for you, but keep trying out new things to figure out the tips that work best.