Avoid techs that I don't need to build my planets
Purge, what do you mean specifically with this?
Wyndstar, thanks again!
This is all rule of thumb.
Since I am using an all factory strategy...I ignore the entire research tree to start with. I also ignore all the military techs (offense, defense, logistics, hulls, planetary invasion/defense) as I only need them when I start contemplating ships. I ignore all influence techs. Since I am playing Gig/Adundant all, I also ignore all the planetary colonization techs, as there are plenty of regular planets around. Also, note that you can invade a planet you do not have tech for...You will still receive taxes and population growth on the planet, after you take it, even if you don't have the tech - meaning I never research the planetary environment techs - ever. You just can't do social builds until you get the appropriate planetary environment tech.
Phase 1:
Production - Morale - Economy - Colonization
I, in particular, want the first couple of engine techs that add +1 to speed, the first econ tech (+10% without building a single building) and morale tech (+15% without building a single building - huge!!!), planetary improvements, basic miniaturization (for colony ships), sensors and to get to enhanced factories fairly quickly (rolls into phase 2). Don't feel compelled to fill every planetary square. I rarely do until phase 3 or 4.
Phase 2:
Production - Morale - Economy - Galactic Resources
Manufacturing centers, star federation. Full Xeno Ethics line (want MCC and ASC minimum). Some basic military techs (often obtainable via trade with minors). Develop a couple of morale and/or economic resources, or get some empire wide morale buildings built. Recently this has been sufficient to carry me to Stock Exchanges without building any earlier economic buildings (super breeders + all max economic stat on racial points + federalists + some morale + very fast research). Without super breeders you will need economic buildings though. Somewhere around phase 2.5 newly colonized planets should be about break even on economics.
Phase 3:
Production - Morale - Economy - Warships
Basically I have people, starports, some galactic wonders, and manufacturing centers...I get to total majesty about the same time I build the first ships (also build up a massive manufacturing planet next to the SCC planet and hopefully a third planet with decent production for quick buying ships for the SCC planet occasionally). I can usually push through medium ships to large ships, some of the miniaturization and about half the missile tech tree, before my planetary ship builds start really kicking out ships. Save logistics until you actually have enough ships to fleet. Start on transports once the warships start to come out. They should take a fraction of the time to build and you really want the fleets (really mini-fleets, sometimes singleton over-powered large ships) and transports to come online at the same time. The manufacturing base accelerates the research at this point...I start laying down Stock Exchanges somewhere in here too.