Here's my own 'tactic' that usually works out pretty well:
Be the leader of a team.
It's simple, and the millitary uses it too. Someone has got to give orders or advice in order to get things going nicely. However, in Tremulous there are a few rules to respect when leading a team
1) If someone else tries to take the lead of the team, by telling people what they should do, respect that.
2) Respect those who do not follow your tactics/lead.
3) Admire and complement those who follow your tactics.
4) Being the number one in the kill-list, or being the team builder works positively on your leading-ability. A dretch that has been playing for 0 minutes and has 0 kills isn't going to be able to lead a team, since no-one would really respect that newly-joined guy and join his lead.
5) If /share is enabled, and you want to take the lead, SHARE! Share even beyond your class-cost (say you're a tyrant and have 9 evos, share 9 or 8 instead of 4). Also, if you're a team leader and hate people who are using low-level classes or equipment (say, dretch-blockers when you're a Tyrant), give them evo points so that they don't have to block anymore.
6) Chat a lot. Don't spam macros, but chat. Type. Be creative instead of "ASSAULT THE HUMAN BASE (ALT ENTRANCE)" 100 times. Ask people if they want to join you in this or that tactic.
7) Having people who know and/or respect you can be very helpful, as they are more likely to join your lead.
If you join someone's lead, let that be known in the teamchat and try to convince other people to join in, too. The more people follow a single tactic, the better it works..
Right, you still with me? Good. Now let's see how this can be put to practice...
One of the things I like doing when I have/take the lead, is a coordinated useful rush, which I usually do when I'm on the Alien team. I'm not sure if this works for the Human team in this exact form and shape, but I guess it does. Coordinated as in get common rules for the rush (time/tactics), useful as in the rules have to be realistic and useful for the current situation. Rushes as Aliens aren't useful AT ALL when the Human team is at its peak with only battlesuits and chainguns or other heavy weaponry. Pick the right time when to attack: when there are a lot of Riflemen or constructors.
Usually, my coordinated rushes are like this:
*Everyone who follows the rush is in it 'for life', meaning that they will suicide and not return to open ground or the base to recharge health/ammo/whatever. This will decrease the time needed for the rush (thus there the rush comes way more unexpected) and it will make it more effective because the player/turret ratio is bigger, and thus more players are 'protected' against turret and/or enemy player fire. The 'Suicide rule' is probably the biggest and most important rule of coordinated useful rushes, ESPECIALLY for Aliens. Drawback is, that when the rush fails, most people will be low on credits or evo points.
*Low-life/equipment stays back until the main attack wave is finished or died down. Low-life versus advanced defense (Teslas!) is worthless. Low-life versus lots of players isn't.
*Target buildings, not players. This is also true for when the Reactor is destroyed or moved (HOW OFTEN do I see DRETCHES go for HUMAN PLAYERS when the reactor is down, instead of MACHINEGUN TURRETS? If you take out the turrets, you'll be able to take down the humans later on in a way longer timescale, and you *will* get your evo points eventually!). Targetting buildings will allow the low-life wave to be more succesful, and since lots of players *will* suicide and die (thus meaning less tyrants) you will eventually get more out of this, too. In addition, two or three high-life/equipment players can take down lots of enemies without defense (buildings), yet they can't when there's a bit of defense left. This rule is really important, too, especially combined with the 'suicide' rule. 10 tyrants each taking down one Tesla means victory. 10 tyrants taking down 3 teslas in total and 9 humans doesn't mean victory per se: that will only delay the end of the game a bit.
So, in short: Never return to the base when you're in a coordinated useful rush. Target buildings instead of players. Do not expect to live: suicide instead. Low-life stays back until the main wave is dead or until most of the defense is gone. The timing has to be great, otherwise the rush backfires and you'll have lots of low-life on your own team (unless your team consists of 9-evo'd Tyrants).
Another, simplified coordinated rush can be made by making a rule where all players should stay on the right side of the corridors.
If a base has two entrances, make sure you use both of these for your coordinated useful rush.
