Secondary professions for a Ranger

Ranger/Warrior

 * Warrior IAS skills, like Flurry and Flail.
 * Warrior attack skills that use energy benefit from the Ranger's primary attribute, Expertise.
 * Rampage as One is used often with zealous weapons for near constant IAS and movement speed boost.
 * The classic Bunny thumper is effective in PvP.
 * Rangers have many defensive stances that can make up for lighter armor when using melee weapons, but are generally less effective then primary warriors for this case.

Ranger/Elementalist

 * Elementalist spells like Conjure Flame can be combined with Barrage to deal extra damage.
 * Mark of Rodgort can be used to spread burning.
 * Since expertise does not affect spells, most Elementalist skills should be avoided.

Ranger/Mesmer

 * Mesmer skills such as Drain Enchantment and Hex Breaker can help fill in gaps in the Ranger line.
 * Trapper teams often use Mantra of Resolve to avoid interruption.
 * Echo chains can be useful when trapping.

Ranger/Monk

 * Mending Touch for condition removal and Purge Signet for multi-hex removal.
 * Rangers have efficient self heals, and should not invest in Healing Prayers.

Ranger/Necromancer

 * The "Touch Ranger" takes advantage of Expertise's effect on touch-range skills. This combined with ranger defensive stances and speed boosts make a powerful build with decent armor ignoring damage and potent healing.
 * Plague Signet and Plague Sending can handle conditions well.

Ranger/Assassin

 * An archery-focused Ranger can employ Shadow Arts skills, particularly reactive Shadow Step skills such as Recall, to keep out of melee range of enemy Warriors, Assassins and Dervishes.
 * Signet of Malice is an effective condition removal.
 * Expertise assassins can be a difficult build, and the few that are effective generally use spammable attack skills, the favorite being Repeating Strike.

Ranger/Ritualist

 * Weapon Spells such as Splinter Weapon and Brutal Weapon can work well with a bow, and combine with Barrage. Nightmare Weapon and Dual Shot create a potent health spike.
 * Ritualist spirits generally require Spawning Power to be fully effective, and generally do not work well with Rangers.

Ranger/Paragon

 * Using Rampage as One with several adrenaline Spear attacks in combination with Apply Poison is an effective way to spread poison and other conditions.
 * Adrenaline shouts and Barrage can prove effective, but are very difficult to balance.

Ranger/Dervish

 * Expertise Rangers with a scythe can be very effective.
 * A bow ranger can take advantage of enchantments like Ebon Dust Aura, Harrier's Grasp or Attacker's Insight.
 * Cheap enchantments, though spells, can add additional effects to bow attacks.