The best laid plans of DM's and players
Roleplaying games are all about planning. The DM, GM, ST, or whomever plans the campaign, plans the adventure, sometimes, and plans exciting moments. The players in turn plan what kind of progression they hope for their character, they plan tactics and ambushes and traps and strategies, everyone has something on the go. But we've all watched at least a bit of T.V, or read a book, or seen a movie. It's common simple logic that if you explain your plan "on screen" then something is going to go wrong, the plan will fail or backfire, and you'll have to fix it. It leaves players feeling like they can't trust their GM, and leaves GM's feeling like they have to trick or manipulate their players in order to make a good story.
How do we reconcile that with a game that is actually about co-operatively telling a story? The obvious answer is that everyone needs to trust eachother more. Be more open about what they want and what they're planning, but there are some cases where that works great and some where it doesn't. So let's through a few dos and don'ts of co-operative planning.
Most importantly: Dotalk this premise over with your fellow players and GM. Maybe you're willing to lay out the entire life plan for your character, but your GM wants to see how they evolve naturally and isn't big on sharing. That's ok, respect that but work together and figure out what sorts of ideas you canplan together.
Combat "Spots": This is one of my personal favourites. Maybe you played a barbarian with a greataxe and improved sunder and you just wanna break everything. Your GM is running you through fight after fight with wolves and monsters. It's completely fine to ask them for more enemies you can sunder stuff to. You can even get more specific. If you know the upcoming adventure is full of lava and volcanoes, ask your GM for an item of fire resistance or immunity and a wizard you can suplex into some lava! Cause that's super cool, but the odds of it happening without you saying anything are really minimal. Combat spots are simple to run, have little impact on the overall story and make for really impressive and amazing fights, I recommend them as a good way to build trust and teamwork.
Mutilation, scarring, and amputation: Woah, that got dark fast right? But the thing is most GM's, not all but most, don't give out scars and limb loss no matter how bad players get hurt, this is because it fundamentally alters a character's appearance, options, andfeel. So when these things are included it's usually a good idea to clear it beforehand. A player telling their DM "Yo, sometime in the next level or so just chop my hand off" is perfect. As is a GM asking a player "How would you feel about becoming a cyclops?". The best part about this is the other players need not know and can get a real stiff shock when it does happen. Obviously this is only appropriate for games with a "mature" audience.
Orders, guilds, and organizations: Nothing helps softball an adventure hook to your GM faster than telling them ahead of time you want to join a guild, or order. And nothing sucker punches the old panic button like NOT telling them ahead of time and just walking into a totally unexplored organization and watching everything freeze, buffer, and stutter as your GM desperately tries to create a dozen npc members, the customs, laws, and history of a guild, and a way to get you back to the quest. Gm's can feel free to make the offer to players before they flesh out a guild, and this helps them decide how much or little work to put into an order, it's a two way street.
That thing, you know, the thing that everyone hates when you do. The thing "That guy" does? That thing: So you know the best way to ruin a party/campaign? Steal from, attack, molest, mind control, insult, or prank your team mates. It starts conflict, it encourages infighting, makes players kill eachother, it's just bad. Unless you plan it with the other player first. Stealing another players magic dagger normally is just awful and mean and probably gonna get you killed or kicked out of the group/party. But imagine instead: planning it out with them as follows. You take their dagger without their character knowing. They fight a foe that they need the dagger against, either due to DR, or tight spaces, or being disarmed w/e. They nearly die because you took it and then you have to save them. You feel super guilty and vow never to betray your friends like that again and all is forgiven since you saved their life and they earnestly believe you've changed. Add in a dash of "Please don't tell the others what I did" and you have a great exchange ripe with character development. You can play out a similar kind of deal with any normally taboo behaviour. Maybe the monk and barbarian get in a fist fight and win eachothers respect, maybe the unruly fighter is mind controlled and intimidated by the mage until he swears loyalty to the party, you can go however you like. But the key is that planning with the involved party is the difference between being awful and amazing.
Secrets: Sometimes you actually want something to be a surprise, a secret, a sudden twist. this can be a lot more complicated, but my best advice for players or GM's is to ask them to help, and to trust eachother. "I have a really cool idea, but I need to fight a red dragon that it's ok to kill" is a fine request from a player and it could lead to a really fantastic and surprising moment. Likewise if my GM ever asked me (assuming anyone ever GM's for me) "Hey, when I throw the ogre mage your way can you try to make sure it survives" I'd be happy to oblige. The kinds of things should be used sparingly but always to great effect.
I hope I've helped you make your games less stressful and all your coolest ideas come true. And remember, being kind is a DC 0 charisma check.