Kill MOBs around starting cities (Mos Eisley is great) for levels 1-3 for all the weapon trees.
For level 4, get some Doc buffs (and Dancer/Musician buffs if you can find them) and head to the Tusken Fort on Tatooine or do Quenker missions on Dantooine. Another great place is the Singing Mountain Clan Cave on Dathomir, just kill the quick-spawn Slaves in the bottom to level quickly with little danger.
Berserk 1 is good to use at lower levels.
Optional: Get some clothes with Bio-Engineer enhancements for Stun/Melee Defense and Intimidation/Warcry bonuses. Be aware that the highest that each of these bonuses can accumulate is +25 (even though it will add up higher, it will only count up to the +25).
Gained by killing MOBs with your bare fists or Vibro Knuckles.
Get some Vibro Knuckles speed sliced (around 1.7-1.5 should be good for speed). Use them instead of your fists, your damage will be slightly reduced, but you’ll attack much quicker!
Use Unarmed Hit 1, Unarmed Lunge 1 (posture down), Warcry 1 (delay), and Intimidate 1.
Optional: You may also want to consider taking some Rakririan Burnout Sauce (Chef food) to increase your Unarmed Damage to counter the damage reduction from equipping the uncertified VKs.
Gained by killing MOBs with a One-handed melee weapon.
Use a Dagger or a Survival Knife to get level 1, a Curved Sword until level 2, and then either the Curved Sword or a Vibroblade for the rest.
Use One-Hand Hit 1, One-Hand Body Hit 1 (hit Health bar), One-Hand Lunge 1 (posture down), Warcry 1 (delay), and Intimidate 1.
Gained by killing MOBs with a Two-handed melee weapon.
Use an Axe to get level 1, a Two-Handed Axe until level 2, and then a Two-Handed Cleaver for the rest.
Use Two-Hand Hit 1, Two-Hand Head Hit 1 (hit Mind bar), Two-Hand Lunge 1 (posture down), Warcry 1 (delay), and Intimidate 1.
Gained by killing MOBs with a Polearm melee weapon.
Use a Staff to get level 1, a Reinforced Combat Staff until level 2, and then a Lance for the rest.
Use Polearm Hit 1, Polearm Leg Hit 1 (hit Action bar), Polearm Lunge 1 (posture down), Warcry 1 (delay), and Intimidate 1.