I use a 3d connexion space pilot with Altium.  Many buttons, and the
knob thing is really nice for 3d views.


Routing:
Place your unmoveable components, then the others, high priority to
bypassing and high frequency paths.

Place crystals and their caps as close as possible to the chip, and
return the crystal caps directly, and only to the nearest ground pin
on the chip that is using the crystal.  From that point flood an
isolated island on the other side of the board.

Select bypass caps according to the frequencies of interest, not 0.1uF for =
all.

I diverge from the conventional wisdom in that I don't use planes to
return power, I route explicit paths that mirror as closely as
possible the sourcing path.  The power and ground route to the bypass
cap, and then to the chip. Never "T" into a bypass, rather make it a
"V" with the cap at the point of the "V". FORCE the current to travel
to the cap, don't give it any other options.

The result of all this is a board that is two layer only, spends
usually $0.00 on emi supression, and passes radiated and conducted
emissions by being so quiet that it is almost completely unobservable
in a GTEM.

RF immunity on our products only needs to be 3V/M, but the last one I
tested in extremis was running as a bare board (no enclosure of any
kind) in the GTEM at a field > 192V/M.  The field measurement
instrument started giving erratic readings above that point, so we
couldn't trust it for higher readings.  We were putting >50W into the
chamber.
--=20
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