There are numerous ways to upgrade many items of Guild Wars 2. Sigils, runes and jewels can be used to upgrade the weapons, accessories and the armors. Some of these items have special upgrade slots and you can use trees/veins or drop-items for a massive upgrade.
Guild Wars 2 – Items Upgrade Methods
Items can be upgraded by the following ways; some have better results than the others.
The gems you collect during gathering can be used to increase the raw attributes. You can fit them into any item, which has an upgrade slot. The method is very useful for the players who are leveling as it increases some combat stats too. Later on, you might want to use these gems for creating the jewelry.
Many creatures such as the elementals drop raw gems and other types of qualities/upgrades (sigils, runes). The higher your level is, more the chances are for these drop items. You will also be rewarded with various upgrades and abilities after completing a story quest. Upgrades and items which are not useful to you can always be sold.
All the crafting tiers are able to produce a different type of armor, weapons and the accessories. You can discover or buy different recipes for creating the items with upgrades. Skilled craftsmen will be able to produce better items as compared to the newbies. Some of these recipes have weird costs as they might ask for rare creature drops. It is still a very good method because you exactly know what you are creating and can use it for yourself or sell it to the other players.
You can upgrade your items by putting an upgrade item on it. These are crests, medallions and the gemstones. Each one of these items have their specific upgrades to the items they are applied on; some will increase the combat effectiveness, and some will affect other attributes. Note that sigils usually provide direct benefits (increased damage) and non-sigil upgrades are for primary/secondary attributes.
Raw gemstones can be found during your roaming sessions and are drop-items as well. Elementals tend to drop them more as compared to other creatures. These are cheap and easily available!
High-level items, they are rare drop items, and you must be level 65 to slot these. Most of these medallions have a hint in their names for the upgrades (Medallion of the Magi increases healing, precision and vitality)
Crests are like the medallions but are at level 80, they have the upgrades hinted in their names. These are rarer, hard to find, high costy items but give you larger boosts and attribute increases.
Weapon Upgrading via Sigils
Sigils are only used to upgrade the weapons. They are occasionally drop-items but huntsman; artificer and weapon-smith can craft sigils as per their capabilities. You have a broad collection, 37 different types of sigils to choose from – at level eighty.
Armor Upgrading via Runes
The runes are just as the sigils are but for the armor and are made by armorsmiths, leatherworkers and tailors. The bonus per each rune depends on your level and the number of runes of the same type which you have on the slots. There are 52 types of runes (level 80) and most of these effect two of your attributes. Just know that it’s better to use the same type runes on your armor set!
There are three types, which determine the bonus levels you can gain by slotting them. Minor: 2 tiers (no level required), Major: 4 tiers (level 39 required), Superior: (6 tiers with level 60 required)
Upgrading Accessories via Jewels
Jewels are similar to the gems, but the difference is that they have higher-quality upgrades. Depending on the quality of the jewel made, they can increase upto three of your attributes. You can have a total of 9 different types of these jewels on level 80.