Everyone knows that fossil fighting involves strategy and complication, but the difficult thing is combining the two to work for you, not your opponent. For example, using three water vivosaurs will get you a team-skill, but is not as balanced as a team with three different type vivosaurs. Even more, are the skills that intertwine. For example, using poison skills are useful alone, but when you team them up with sleep skills, you prevent healing with rallying cry, or anything else. Here are some useful ways to bulid teams.
1. Have a varied type team. TEAM SKILLS ARE NOT OVERLLY IMPORTANT! It is better to have three uncompatable Vivosaurs, than having the same type. This also goes for the abilities and strong suits of the vivosaurs. You don't want three support, or three attack instead of having one or two of each.
Another opinion: However, should you be able to do team skills without having to use the same type of vivosaurs is possible, and deadly when well-supported. If you want to try setting up compatible teams, see the list of compatible vivisaurs (usually involves same diet).
2. Keep your team out of certain habits. For example, don't have a team that relies totally on position swapping- the chance that one of your opponents having an excite skill is high. Also, don't rely on one vivosaur. Have at lest two decent attackers.
3. Make sure that your team has overlapped all of the possible status skills, and if possible, as many abilities as possible (except for berserker - don't have three hopters) In this way, you can guarentee that your opponent won't be totally safe, and also, this strategy helps you to last longer - a scared, or sleeping team can't really do much.
Another opinion: Enrage skills are almost always fatal, as they make attacking vivosaurs almost useless. Not to mention that they are very common among vivosaurs. Almost always carry a vivosaur with Rallying Cry in wi-fi battles, because strategies involving enraging a whole team are very common in that area.
Finally, some good moves and abillities to put together
Sleepy and Rallying Cry - allows attack on first turn
Parting Blow and Law of the Jungle- power boost
Charge and Super Enflame - does a lot more damage
Confusion Skill and Payback - reduces chance of inflicting damage
Team Swapping skill and Excite Skill - mess up team and prevents fixing.