I have a basic commanding structure with two starts...
Good Marine team Start: IP's, Armory, Arms Lab, mines (one pack)
Unknown (Bad) Marine Team: IP's, Armory, TF, Elec
Rest of Game:
Find hive and head in opposite direction. Use two groups of marines. One group captures nodes (I don't elec unless really crappy marines, if OK marines, elec high alien traffic nodes, good team, I elec nothing but hive RT's). The other group go toward hive and kills all nodes. This keeps aliens on defensive while marines inhibit their res flow and increase our own.
As soon as Arms Lab is up I upgrade ARMOR 1, allows my men to stay in the filed longer b/c they take more damage. Then Obs, then phase, Armory upgrade, lvl 1 Weapons... etc. From there I go by how we're doing. If we're dominating, I push on hive and upgrade quickly. If we're being pushed, but stable, I lock down key areas, and have marines scout for nodes and defend nodes. If we're being overwhelmed, try to lock down one hive and 2 nodes, keeping aliens contained as much as I can.
I do have abad habit of giving up if an expensive attack fails, i.e. siege rush that is destroyed. I'm working on having backups, but I'm still learning how not to put everyhting into one attack. One of the best comm's I know is The_Spectre on CoFR. Somehow he always manages to have 100+ res most of the time and upgrades going. I guess I spam health too much....