Be helpful. I have built a significant network of useful people, and in many cases the relationship started from from me offering to do small favors - as small as helping put away chairs after a lecture - and striking up a conversation.
Addendum: while on occasion I use this technique consciously, there is some concern about seeming transparent (still don't let this stop you, especially with unique opportunities at stake). Best reward yourself for being a helpful guy/gal, make it part of your self image. As your status grows it will be quite natural to offer help to important people (I once got the nerve to offer help to a very rich mayor of a major US city, as I had something to offer. Nothing came of it, but still).
This is an extension of a comment I made that I can't find and also a request for examples. It seems plausible that, when giving advice, many people optimize for deepness or punchiness of the advice rather than for actual practical value. There may be good reasons to do this - e.g. advice that sounds deep or punchy might be more likely to be listened to - but as a corollary, there could be valuable advice that people generally don't give because it doesn't sound deep or punchy. Let's call this boring advice.
An example that's been discussed on LW several times is "make checklists." Checklists are great. We should totally make checklists. But "make checklists" is not a deep or punchy thing to say. Other examples include "google things" and "exercise."
I would like people to use this thread to post other examples of boring advice. If you can, provide evidence and/or a plausible argument that your boring advice actually is useful, but I would prefer that you err on the side of boring but not necessarily useful in the name of more thoroughly searching a plausibly under-searched part of advicespace.
Upvotes on advice posted in this thread should be based on your estimate of the usefulness of the advice; in particular, please do not vote up advice just because it sounds deep or punchy.