This may seem like a silly tip, but I swear it works.
Give yourself a secret nickname. This is going to be like your super-hero identity for creativity. For instance, perhaps you could call yourself "Genius Pants." Now, when you need an idea fast or you start to get stuck, just say to yourself, "What now, Genius Pants?"
Once you do this, it activates a whole other part of yourself. The part of you that is energetic and eager to please. The part that is brimming with ideas! Great ideas!
Then, after you're finished, just say, "Thanks Genius Pants, you are awesome."
The first step is to choose your nickname. I recommend having more than one word in your nickname. The first word can either be a positive adjective, like "genius" or "amazing," or a title of some kind, like "princess" or "mister." Then, the second word can be any noun or another positive adjective.
It can also be fun to add a "Mc" to the front of the second word.
Here are a few samples:
Pick a stupid name, but a name you like. Don't tell anyone. Sharing it will make it work less. It's a nickname for you to use for yourself.
If you come up with one that you aren't going to use, just leave it in a comment. You might be helping someone else.