It occurred to me recently that there doesn't seem to be a place to share simple FRED tricks - there's the wiki tutorial section, aye, but not everything warrants an entire tutorial page, and an easily-scrolled-through list can't hurt, either. With that in mind, here are a couple of mine. Post your own!
Un****ing support ships in escort missions
Ah, we've all had that experience - the NTF/Vasudans/Shivans/random anime bull****/whatever attack on the GTCv Primary Objective has slackened off, and it's a great time to rearm, except the support ship is 6432653464 kilometers in some useless direction because the AI doesn't know to follow you. Let's fix that.
( when-argument
( any-of "Support 1" "Support 2" "Support 3" "Support 4" "Support 5" )
( is-in-mission "<argument>" )
( add-goal "<argument>" ( ai-guard "GTCv Primary Objective" 20 ) )
( invalidate-argument "<argument>" )
)
As soon as a support ship hits the field, we give it a low priority guard order on the most important friendly ship. (This could also be an installation or the player, depending on the type of mission.) This guard order won't interfere with its ability to rearm things, as those are issued at a higher priority, and once its done rearming, the highest priority order will be the guard order once again.
script-eval-block and <argument>
This one's a little hypothetical, but, put simply, if one argument to script-eval-block is just <argument>, it'll be replaced like any other. This can be used quite nicely with Axem's in-mission jump script:
( when-argument
( any-of "Alpha 1" "Alpha 2" "Alpha 3" "Alpha 4" "Support 1" )
( < ( hits-left "<argument>" ) 40 )
( script-eval-block ( "IMJump:To('" "<argument>" "', '" "<argument>" " runs away')" )
( invalidate-argument "<argument>" )
)
Pay attention to the quotes!
Guardianing the player's comms
This isn't so much a trick as something I've been wishing would become standard practice ever since BtA did it. Guardianing the player's comm system at 1% is almost completely mechanically irrelevant (it does mean the player will eventually regain the ability to issue orders even without a support ship, but eh), and saves the frustration of arbitrarily missing out on plot points.