Santa Monica (KSMO) Tips or Gotchas?

I'll be flying one of our 172's down to Santa Monica (KSMO) sometime in
the next few weeks, probably this coming Friday (returning the following
day). I'll be arriving from Oakland, stopping somewhere like Santa Maria
or San Luis Obispo for lunch before arriving IFR into SMO with a couple
of passengers at around 3pm.

Any tips on Santa Monica airport and associated FBOs? I'm familiar with
the area from the ground, but haven't flown into SMO itself before, and
don't want to miss any less-obvious gotchas or make a major faux pas or
something. And for the IFR bits -- should I expect the Fernando 5 /
DARTS arrival pretty much as-is, or should I expect to get a more
complex airways routing -- or just a series of vectors? I'm happy with
any combination, but it'd be nice to be forewarned...

And one dumb question -- do you tip FBO staff if they've parked your
plane for you somewhere and retrieved it again? OK, since this is LA and
it's a species of valet parking, of course you do, but how much? They
did this once (very competently, with impressive attention to detail) on
a crowded ramp at Santa Barbara, and I hadn't a clue what to give 'em...

Thanks,

Hamish