Elements are nice and easy in RF, using the correct talic against the monster you are fighting will give a massive boost to your damage, the element system works as follows:

Water > Fire > Earth > Wind > Water

For PvE, a popular and safe upgrade for an Intense/Type B weapon is to add an elemental talic appropriate for the monster you are killing along with a single Chaos talic (10% Crit chance for one talic). The Elemental talic gives a huge boost in PvE, similar to going +4/+5 with keens!