Chaos Space Marine Terminators
Chaos Space Marine Terminator Squads should have a purpose when they are designed. They can be assault squads or Devastator squads, or Tactical squads in armament.
Assault sqaud - For this role, go heavy on assault weapons and leave out the heavy weapons. You might also wish to make them Khorne Berzerkers or Plague Marines. The Khorne Berzerkers are frenzied, and have Chaos armour to protect them, and they have the Furious Charge, which gives them triple move instead of double normal move for charging. The Plague Marines gain a +1 to their Toughness.
Devastators - I set these squads up as three Terminators, two of which have heavy weapons. The only special cult I would make these would be Plague Marines for their +1 Toughness. I do not personally like to give Terminators the Thousand Sons cult, even though it gives them immunity to psychology, and a psychic save, its vulnerabilities in my opinion outweigh this.
Tactical squad - I usually organise these five-figure strong with one heavy weapon exactly as you would a Space Marine Terminator squad.
There is one special Terminator squad worth mentioning, even though it takes quite a bit of conversion. This is a Noise Marine Terminator Squad. They can be very potent and they make for some beautiful models.
Veteran Chaos Space Marines
These are some of the very best troops available to any army. They can be used as either of the three basic squad types, Assault, Tactical, and Devastator, and they can infiltrate, as long as no one in the squad (this means Aspiring Champion, Champion, etc.) is wearing Terminator armour.
Assault squads - These should be armed with the weapons needed to do the job. Do not fall into the trap of overarming them. Only the most powerful weapon that the figure has is counted for doing damage in hand-to-hand, the other weapon only supplies an extra attack and parry, and can be nothing more than a sword. Purchasing two exspensive weapons for assault troops is a waste of points. You should also think about the opponent you will be fighting when purchasing their weapons.
Tactical - What I would do with Veteran Chaos Space Marines is create a squad that has the Tactical Marines' capabilities with chainswords and/or chainaxes added. Somewhat like the Space Wolves Grey Hunters.
Devastators - I would organise these in three figure units with two heavy weapons, and use them to support my assault squads and tactical squads, also to pick off enemy vehicles and/or characters. They can also be used with heavy bolters to cut down opponents' troops to good effect.
I use my Veteran Chaos Space Marines to make infiltration attacks, to set up ambushes, to set up in an area where they can flank the enemy, and also as a tactical reserve to react to any area where I need their higher-than average abilities.
Chaos Space Marines
Chaos Space Marine Squads are the backbone of your army, and they may be used as either of the three basic Marine squads. They are used in the same fashion as the same type squads are used in a loyal Space Marine chapter, with one exception: Devastators.
Devastators - I use these in three man squads with every man carrying a heavy weapon. I usually arm these with two heavy bolters and either an autocannon or a lascannon, depending on the mission I have for them, or I will arm them with two lascannons and one autocannon as tank-hunters.
Plague Marines
These are nasty assault troops, but I do not consider them to be as good as the Khorne Berzerkers in this role, and they cost the same points.
Khorne Berzerkers
These are the ultimate assault troops! But they should not be wasted by having to cross large areas of open terrain. Get them into close combat quickly, and don't give your opponent the chance to cut them down with firepower.
Thousand Sons
These are the same as your basic Chaos Marines, with psychic saves added to them, and the vulnerability to the Drain Energy card. They have a few other immunities, such as psychology. They make good Tacticals and Devastators.
Noise Marines
These are special case. They end up being very nasty Tacticals with their Sonic Blasters and one model having a Blastmaster and one model a Doom Siren. I also like to give these photon flash grenades when fighting against IG, Orks, Tyranids, etc.. The Noise Marines are great for nullifying psykers, their only problem is they also affect yours, so keep them away from your psykers. On the other hand, Dameons quite like their Psychic Cacophony.
Chaos Space Marine Bikers
Give them a powerfist or a chainaxe to make hit and run attacks with. A neat trick is to set up a squad of three, give them powerfists, and use them to hit and run against enemy vehicles. Bikes are great for making mobile flank attacks, but don't try to stuff them down the center crossing large areas of open terrain.