my build focuses on letting singed be a tank on legs by taking a **** ton of damage and then doing alot of damage over time with poison, alot of slows and flinging people in the air.

early game you wanna focus on harassing the weakest champ in your lane unless they have a jungle (you wanna try and take top all the time), don't use poison on creeps till you hit 2nd point on poison. try to hug tower as much as you can but never let exp go to waste, you can stay in lane a long time when you get catalyst the protector.

mid game starts around when everyone is lvl 11 and should be ganking or switching lane, don't leave your lane until you destroy your tower because it will make your farming easier when their tower is gone for more room to run down then up the lane with your poison, if team fights occur your job is to run in fling a weak champ back and run around until you think it is safe to run away, because you should be the only one in the fight against the other 4 or less champs, they should have taken damage from poison trail they "will" chase you until they die so by then the champ you flung should be dead and the rest of the team will join in on the fight.

now you should have rylais crystal scepter which is your must have item because all three of your abilities will now slow the other champs and your mega adhesive does a 80% slow which is amazing because it pretty much just keeps them in one place, but again your job is to fling and poison and now that you have Resistance and health you now are a tank and they all just get kited with your poison slow :D

this is my first time doing a build and hoping to do others soon but it seems i lack info on other topics so just tell me if this was helpful at all :D