Secondary professions for a Ranger

Ranger/Warrior

 * Rampage as One combined with skills from the line of Hammer Mastery, provides quick adrenaline gain. These rangers are often referred to as "Bunny-Thumpers". (This is because of the way they run when carrying a hammer.)

Ranger/Monk

 * Mending Touch is useful for condition removal and Purge Signet is useful for multi-hex removal.
 * Rangers have efficient self heals, and should not invest in Healing Prayers.
 * Resurrection skills such as Rebirth are useful on primary rangers, as they tend to have better survivability than other professions and can save a party from a near Party-wipe.

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.

Ranger/Mesmer

 * Echo chains can be useful when trapping.
 * Fevered Dreams can be used to spread AoE conditions.
 * Greater Conflagration and Winter combines well with Mantra of Frost to reduce physical and elemental damage to almost nothing.

Ranger/Elementalist

 * Elementalist spells like Conjure Flame can be combined with Barrage to deal extra damage.
 * Kindle Arrows may also be coupled with Conjure Flame to deal a substantial amount of damage without the necessity of a fiery bowstring.

Ranger/Assassin

 * Signet of Malice is an effective condition removal skill.
 * Expertise lowers energy cost of dagger attacks, making skills like Repeating Strike, more maintainable. This can also be used to make longer use of Moebius Strike and Death Blossom.

Ranger/Ritualist

 * Weapon Spells such as Splinter Weapon, Nightmare Weapon and Brutal Weapon can work well with a bow. They combine with Barrage and Dual Shot to create a potent damage spike.
 * Binding Rituals are affected by expertise, though Primary Ritualist's are often better Spirit Spammers.
 * The Ritualist's reusable resurrection skill Death Pact Signet.

Ranger/Paragon

 * Energy-based spear attacks are affected by Expertise, thus allowing a Ranger to use them at reduced cost.

Ranger/Dervish

 * Rangers can successfully use this build to create a new form of condition dealing. By using the elite Ebon Dust Aura on an ebon bow, in addition to the other condition causing enchantments the dervish has to offer, this ranger has the ability to cause serious damage and provide successful defense against warriors and assassins.