Spend some silver to upgrade your base when possible. Do not put too much effort into its layout, however. It will never be attacked by other players. Tents, chicken coops, and sheds will help maintain your group's morale, as well as provide essential supplies. As your base gets larger, you can eventually expand beyond the basic square of landscape that it started on. Place advanced structures and defenses to get additional benefits and help repel attacks from NPCs and other players. Every structure provides a timed bonus of silver currency which grows as the structure is upgraded. You can bypass a structure's construction time by spending gold bars. Your starting stack of 500 bars will allow you to upgrade some of your starting structures to get an early boost in morale and silver income.
Survivors
Besides leveling your own character, remember to train and upgrade your survivor squad. This will allow you to progress to higher level areas and unlock new skills and special abilities for certain survivors. When get new survivors, examine their skills and abilities to see if they can train one of your current survivors. A strong attack team works well against large numbers of zombies as well as other teams in Versus mode.
Targeting
Zombies that are marked with a pink indicator are ones that must be killed for a mission. Instead of first selecting a target to attack and then tapping the small "Attack" icon that appears below them, just double tap a target to immediately select it and attack. Be careful when attacking an enemy that is in a close group, as there is no way to back out of the attack.
Various strategies
Destroy buildings to get money and a chance at finding items. After enough zombies have been killed in an area, that location will level up. Stronger zombies will be present, but the rewards will also be better. If you are low on energy but close to the next level, hold off on using an item to restore it. Your energy will completely refill after you level up. Fuse matching characters when possible if the main character is not at maximum level.