Specifically declare what prep spells are being cast, if any, and on whom. Get clear agreement with both caster and target of the spell. You should be ticking off resources as they are used. Spell casting should be very clear on what is being done. No retroactive casting or un-casting.
Planning. With no more extended planning allowed during combat rounds (it takes our group a heck of a lot longer than six seconds work it out in real time, its not at all realistic to do it while dodging foes), planning will have to be done ahead of time.
The party may have to disengage the enemy, retreat, plan
their actions, then engage again.
Oh, and Coleslaw says to almost always
expect a fireball (or some sort of area effect spell) from him in the first round.
"Are we ready to enter battle and die with honor? Or shall we sit about muttering and nattering like old women! It is a good day to die!"
Individual actions are no longer open to group discussions during combat rounds. During your round your character may shout encouragement or up to 6 seconds of suggestions, but that’s it. Encouraging players is always OK, "Roll a 20!" but telling them what to do or what they would do, or what they should do is right out.
When your initiative comes up, you have six seconds to announce your action (decree it or lose your action). If you recall, each round is only supposed to be six seconds anyway. Dice rolling and resolution takes place afterwards. You do have all six seconds, so you do have a very brief moment to change your mind…
No "My character would have known that". Players should know the character, and think of this as the "Fog of War". Lapses in DM description may be an exception to this rule. Maybe. But lapses where players did not listen while the game master was describing the action are not at all going to be allowed.
All spells, feats, skills, etc, must have book and page number noted. At the very least, we can cut down page shuffling by knowing exactly where to look in the books.
Open discussion is still acceptable during non-combat rounds, but once a player declares an action, no matter how stupid, we go with it. "Oh, I fireball Bukeboom's head" is a declaration of an action, and if not negated by the player inside of 6 seconds (with no help from other party members), it goes off.
If a lot of people try to do things at once, we go to combat rounds and initiative orders to determine actions.
The following suggestions are paraphrased from the Players Handbook P126:
Attack and Damage: Roll your attack die and damage dice at the same time. If you miss, you ignore the damage roll.
Multiple Attacks: Use dice of different colors so you can make your attack rolls all at once instead of one at a time. Designate which attack is which color ahead of time.
Concealment Rolls: If you know what your chance to miss is because of the targets concealment, you can roll it along with your attack roll. If the concealment roll indicates a miss, just ignore the attack roll.