Hi
When you have a transistor designed for LNA design, it generally comes with data like NFmin and Γopt. NFmin is the minimum achieveble NF of the amplifier WHEN the source reflection coefficient(Γs) is equal to Γopt.
As you properbly know, to have maximum power transfer of an amplifier you need to have conjugate match at input and output or expressed in another way: Γin=Γs and Γout=Γl.
You can make a perfect match at the output, but the input is where you have to make a compromize between low noise and high gain as the source reflection coefficient that maximizes your gain is not the same as Γopt which minimize your noise!!
A procedure which can help, is to plot the noise circles and available gain circles in a Smith Chart and then do it for different bias points. You can do this by hand or use som software(@DS, MWO, etc..). You can plot Γopt and also Γs. I know @DS has a function that can plot the Γs that gives the maximum gain. These two points should be as close to each other as a first starting point.
I hope this helps, it is somtimes a bit difficult explain things only in writting.
But give a message if you have more questions.
Regards