Sejuani should be played as a total lane bully. If you start with Red Crystal and have the runes and masteries, your lvl 1 HP will be just over 800. That gives you a huge advantage against most champs top lane. Why? Because your main source of dmg scales off hp, so not only do you make yourself tanky, but you give yourself strong early game dmg. I don't recommend boots first primarily because 1) your q should be your initiator and boots don't effect that speed at all 2) your passive slows enemies sufficiently to compensate for your own lack of speed 3) the initial health along with your skill set will let you win just about any fight 1v1 in early game and 4) you have ghost, so running should be no problem especially with your q to escape also. Your combo should be initiated with q to apply passive, activate w to start loading out the damage, keep auto attacks on target as passive amplifies w damage, and if they start to run away or out pace you, you can use your e to slow them even more. E is also a good finisher move, so try to save for the end of fights if necessary. Often times they will try to run right before you kill them, and this move secures your victory. I wouldn't recommend trying to fight until you hit lvl 3, although you can at lvl 2 with just q and w. Anyway, this is all I have time to write. Hope you like it.