TvT Types

General Rules:

GP/Grenades need to be reduced. No one wants to be spammed with 20 GPs.
Know the strength of each forces equipment and balance the numbers accordingly
Be very clear on the mission briefing for each side. Make sure each side understands their objectives.
The prime different between TvT and SPCL is TvT should require planning and team coordination. If it does not need this, please view SPCL guidelines

Attack vs Defense

Straightforward type of TvT. One side has a position and the other side assaults. Some guidelines for these are:

Little to no GPs for this type. Little meaning about 4-6 (2-3 per grenadier) per squad. Again, its just too easy to shell a position and then walk in after you have blown it to pieces. GPs will need to be used tactically
Focus on giving smokes to leaders. This helps players move around and gives a fighting chance to the attackers to move up
Armor makes a difference. Be sure its balanced for each side. Level 1 vs Level 3 armor and even numbers is a no go.
Be sure to give fortify tools and adjust the money value as needed. If you want them to really dig in, increase the pool or decrease if you think they don't need as much.

Attack vs Attack

Another Straightforward type of TvT. All sides are attacking a point/area until there is a clear victor. These usually are a last-man-standing. General guidelines for these are:

Reduced GP counts for these but not near as much as the previous. Average of 10 per squad will be permitted as all teams should be moving and have room to adjust to fire as needed.
Make sure that the starting point to the objectives are balance. This means it takes equal time to arrive at the location from both sides. Factor in terrain, obstacles like fences or buildings, and the overall play area.
Make sure both sides have an even gear loadout. Same armor values, a similar weapon platform (no pistols vs shotguns), and any kind of launched/thrown ordinance.

Capture

One of the more difficult TvTs to make as you will need to focus on making sure all sides involved will encounter each other as well as be able to complete the mission provided. These are usually your multiple objective holds, HVT capture and extract, and capture/destroy the enemy base. Guidelines are the same as the Atk vs Atk idea as well as:

Objectives need to be even to all sides involved. Some exception can be made such as a 3 way with one force being smaller but better equipped.
Be sure all tools needed are given to the player i.e(handcuffs for HVT capture, explosives for destroying objectives, ect)