I have sworn by Hagen Prime because of the mixture of vitamins in it as well as the fact that it also provides amino acids and other things that birds need which most supplements don't include. My cockatiel has always been especially picky with eating and I had resorted to mixing Prime in all of my birds' water dishes but it can sometimes create an unpleasant odor after some time and with 2 of my 3 birds loving to dunk their food in their water it got ugly after less than a day at times. I tried putting the powder on top of certain treats but they were smart enough to eat around the powder. I finally came to this conclusion.
Get a slice of bread (See Note Below) and sprinkle about a tablespoon of Hagen Prime all over the slice and then rub it in with your fingers making sure that the entire face of the bread is covered. Seal the slice in a zip lock bag and leave it sit for at least a few hours or overnight. Because of the contents of the powder and the moisture in the bread the soluable parts of the Prime work their way into the bread reducing the areas that the bird can eat around. Once it's disolved overnight you can break off a small peice of the bread and feed it to your bird and then refrigerate the rest in the zip lock bag.
Important notes about bread:
First of all it is important to understand that bread it's self has health benefits for birds such as calcium and fiber, however, you have to remember that most breads contain yeast and will generally expand in the stomach. Because of this you do not want to feed your bird a large amount of bread. If you were to give your bird an entire slice of bread he may eat more than he should. This is especially true with smaller birds such as cockatiels.
Secondly, you can use pretty much any bread for this that you'd like but I use Potato bread for a couple of reasons (other than the fact that I usually have it). Because of the potato mixture of the bread it remains lighter and fluffier and holds moisture longer. As a result it absorbs the prime better than white bread (as far as I've noticed).
I'm sure there are some wild opinions on the use of certain types of bread because of sugars and such. In my opinion, however, the amount of sugars and other "non-healthy" substances in a tiny peice of bread is low enough that it won't make much difference. My birds absolutely love this, seemingly even more than plain bread at times. The Prime does have a pleasant scent and taste for birds so I'm sure that helps.
Any comments on this are welcomed! If you have birds and try this, please leave a comment and let me know how they like it.