Hmmm lets see. My plan is to research the four techs (Alpha, CB, CL & Mon) plus the off tech for Monarchy, then look around & see what to do next. Sometimes, a hut or two will adjust the original plan with other interesting techs; sometimes searching will show neighbors too close or barbs.
Assuming no problems, I usually use BW for the off tech (a wonder, a defender and a tech towards trade), but writing is also very attractive (dips for search, and buying barbs; a tech towards Phil & a free advance). Given enough room for a dozen early cities and a safe enough environment, Ill opt for Phil as the next goal (Write, Lit, Myst, Phil) noting that the path improves the one or two temples that might be in place (capital & SSC), lays the foundation for Republic, but there is also pressure for Pot and Mas (both for wonders) soon. If contact occurs, Ill swap for any & all techs depending upon the other civ -- I prefer to postpone early wars.
I confess to being seduced into HBR when I open the map & see lots of grass/plains in view -- rapid search has its own set of rewards. Also I can be pushed off the Monarchy path if I see two many foreign units too unfriendly too soon -- I often start with CB, then will go Alpha, off tech, CL, Mon -- but if I have CB, Alpha, BW & see some pressure, the HBR & Poly become attractive. If it is rough terrain, then WC & IW become more interesting since two move units wont have the second move anyway.
One of my foibles is getting around to the water late. If I have enough space to grow on my own rock, Ill postpone Map for the first twenty techs+ and happily build a dozen cities & a few wonders; a contact for a couple of trades or MPE may give me enough edge with techs that GL is less useful (or if Im listed as not number one in science, then GL might become a priority
)
So my starting blocks of a tech tree look like: Monarchy
Phil
Trade
techs for early wonders/road to Eng
Astro/Med (the SSC development plan).
[dance] 
