Try micronized creatine powder.
For mixing, you can mix with anything that is not acidic.
If its not fully dissolved, add more water and try harder
After reading and reading, I will prefer to use it as post wo.
Now my question is how do you guys measure the 5 gram serving?

Oh i am not sure if mine come with the spoon or not.
Do you mind posting an image of your spoon on your finger?

Yeah, if you have the provided scoop, pls post a pic. Just want to have a rough image how a 5 gram serving should be.
Currently still using teaspoon. And there are quite a number type of teaspoon (different shape and size).

If you are not on low-carb diet, then you can try to mix it with glucose polymer like what 4Rings already said.
For me, I mix it with whey only. I usually take it after eating 1 banana (too lazy to use blender).