Personally I use SeaDragon's PlayerSkillBarPlugin to do that, as well as my own customized filter to remove what I consider useless skills from the bar :
Code:
Plugin = Hud.GetPlugin<GLQ_PlayerSkillBarPlugin> ();
if (Plugin != null) {
GLQ_PlayerSkillBarPlugin PlayerSkillBarPlugin = (GLQ_PlayerSkillBarPlugin) Plugin;
//When the AllSkill = false, the skill filter is turned on, You can find the SNO value in IPlayerSkill from here : \interfaces\data\player\powers
PlayerSkillBarPlugin.AllSkill = false;
// Decide which skill to show for each class
PlayerSkillBarPlugin.Barbarian = true;
PlayerSkillBarPlugin.AddNames ("79528", "86989", "79607"); // Ignore Pain, Seismic Slam, Wrath of the Berserker
PlayerSkillBarPlugin.Crusader = true;
PlayerSkillBarPlugin.AddNames ("290960", "342279", "342280", "342281", "269032", "243853"); // Laws of Fate, Hope, Justice, Valor, Akkarat's champion, Steed charge
PlayerSkillBarPlugin.DemonHunter = true;
PlayerSkillBarPlugin.AddNames ("365311", "130695", "302846"); // Companion, Smoke Screen, Vengeance
PlayerSkillBarPlugin.Monk = true;
PlayerSkillBarPlugin.AddNames ("317076", "96215"); // Inner sanctuary, Serenity
PlayerSkillBarPlugin.Necromancer = true;
PlayerSkillBarPlugin.AddNames ("460358", "465350", "465839"); // Army of the dead, Simulacrum, Land of the dead
PlayerSkillBarPlugin.WitchDoctor = true;
PlayerSkillBarPlugin.AddNames ("117402", "347265", "106237"); // Big Bad Voodoo, Piranha, Spirit walk
PlayerSkillBarPlugin.Wizard = true;
PlayerSkillBarPlugin.AddNames ("134872", "243141", "168344", "167648"); // Archon, Black Hole, Teleport, Archon Teleport
}
(just add in your customize function in PluginEnablerOrDisablerPlugin.cs)