Link to this build: 22 Assassin / 22 Riftstalker / 22 Bladedancer
This spec was last updated for RIFT 1.10.
If you are not geared enough (ID or HK gear) then I would highly recommend this point distributions instead, nothing else changes like macros, etc.
Alternative solo build for less geared: Link to this build: 20 Assassin / 24 Riftstalker / 22 Bladedancer
This alternative build gives you an additional 6% reduced damage taken instead of 3% as well as improved meditative trance which increases the healing by 50%.
You will use these as much as possible, when on cooldown and only every 10 seconds or longer. The reason why you will use it every 10 seconds or longer is because of the different buffs you get depending if you are using either Stalker Phase or Guardian Phase at the time.
If you are in Stalker Phase and plane shift, you will get both Cruel Vengeance buff for 10% increased damage and the Stalker Phase buff for 10 seconds of 15% increased damaged. If you are in Guardian Phase you will Rift Guard (absorbs damage), Planar Vortex for 8 seconds and Cruel Vengeance.
It would depend on your gear level as to which finishers to use first, second and so on but for my ID/HK gear level I use Annihilate first for the Attack Power buff, then sometimes followed by either Guarded Steel the 30% armor increase and to put up Rift Guard for or Dauntless Strike for the 5% increased critical hit.
I normally only use Meditative Trance when I am in trouble and with low health. Also remember that you have Rift Scavenger available to you when you are low health, so build and do not use the combo points on a target with the lowest health and kill it to get your unused combo points refunded to you for 6% of your maximum health.
Twin Strike awards 1 combo point, so you can easily build combo points to use Compound Attack or any of the other many single target finishers. Rift Disturbance as of 1.8 does not award 1 combo point, the tooltip is getting fixed in 1.9.
If you are not geared enough, I would strongly suggest using Guardian Phase majority of the time, you will still deal a lot of damage especially when teleporting a lot so you can throw up Planar Vortex.