Good lather is imperative, and the chin is the hardest part to shave for everybody.
IMO you have two real choices for soap. You can drop a soap puck in a coffee mug and work up a good lather with your brush in the mug. Don't use too much pressure, and you'll soon find how much water you have to add to get a nich thick lather. As others have said, if it really sucks just pour it out and start over. Don't rush. I'd say that whipped cream analogy is a good one, and if you take your time you find the lather will build to that consistancy.
The other choice is to use a soap like Proraso which comes in its own plastic tub. Just work your brush over the soap and when the brush is picking up the soap paint it on your face, a section at a time. Then, work up the lather directly on your face using more or less water on the brush to get the consistancy you want. This method actually takes a little less time than working up the lather in a cup.
Sounds like you are off to a good start. You just need to take your time. Let us know how it goes.