Over on Reddit user soooooil has posted about his work in building an LNA, including etching the PCB. On his imgur page he shows the design and construction process through images, before showing the final result in SDR#. For the LNA he used a ERA-3SM+ MMIC which has 17-23 dB of gain and a NF of 2.6-2.8 dB. While the noise figure is fairly high for an LNA, it is still likely lower than the RTL-SDRs internal amplifier noise figure which is around <4.5 dB.