Theory crafting is one of the more nuanced elements in Path of Exile, and is the method by which players build mods. New players usually tend to approach their builds using a variety of strategies, ranging from trial-and-error to detailed, scheduled acquisition of PoE items. Nevertheless, there is usually a method to the madness, as many players have come to learn along the way.
For some, picking up elemental resistances in the skill tree is a preferable route. Free resistances means that the required gear and effort involved in picking them up is minimal, and upgrades can be accomplished cheaply. This prevents stagnation when players are in the process of leveling, and affords them a high degree of flexibility when experimenting with unique or rare items later in the game.
This strategy, while affording the player a consistently reliable chance of surviving the maps, is not without its pitfalls, however. Builds that come about from this strategy tend to have low damage ratings and increased time to clear the advanced and even mid-level maps.
Other players use the skill tree to obtain items that enhance a variety of different defenses as well as related keystones. For example, by preferentially picking up life-based totems, they tend to gravitate towards totem nodes, simply because of how close they are to life and armor defenses. Defenses are usually very strong items on the skill tree, and these items affect how players deal damage.
Using unique Path of Exile items in the majority of the slots of any given build makes using the free resistances worth the trouble. While picking up as many jewels as possible is definitely an appealing strategy, ultimately this depends heavily on the path. Jewel sockets play an important role here: obtaining all jewel nodes within two skill points away from the main paths seems to be most viable.
The decision whether to use Singularity instead of a rare sceptre will undoubtedly come up, especially when seeking to explore the potential of different builds. As a rule, uniques should not be used simply because they are generally good or strong. Rather, players would benefit from using uniques because their properties are compatible with the rest of the other assets. They must be good in context with the rest of the build.
It is important to note that elemental resistances have a finite limit to upgradeability, whereas damage and health do not. With that in mind, taking elemental resistances is a viable strategy, but only to a point. Although it is a challenging approach, players can opt to tweak rare sceptres with resistances, especially since not every unique item has an equivalent rare. This would be especially difficult for “low lifer” players, since they would have to cap resistances such as chaos at a reasonable level (75% or so) to be safe from multi-projectile Vaal constructs and certain bosses. A wise addition to this strategy would be to allocate points towards skills that are near completion for a given build, which results in a highly viable character despite still having room to grow.