For these, I used blueberries, yogurt, flax seed, and some honey. To fill these, you just need to use a funnel to pour it into the pouch. There is space on the packaging to write the flavor and date they were made. I would recommend writing on them BEFORE you fill them, because it'll be a little squishy after you fill it. Once you fill it near the top, seal the top by pressing on the top zip part. Put them in the freezer STANDING UP! If you lay them sideways, some may spill out and you don't want a mess everywhere. Overall, these worked great and didn't spill in my freezer. It was a little hard to open initially after taking it out of the freezer, so you may want to de-thaw it or rub the top for a little bit to make it easier to open.
In summary, these worked great and were easy to use! I am happy I got these and was able to make these healthy treats for summary.
Want to check this out for yourself? Here is the Amazon product link:
*I received this product at a discounted price or free in exchange for my honest and unbiased review*