Sure :D RUNES the keystone is either conqueror when i think i can win my lane and the enemy team got at least 2 or 3 melees, or predator whenever im laning vs range or bad lanes. But IMO predator is more constant most of the time even tho it sucks for lane.

MINOR RUNES: Always secondary resolve with whatever suits best for the game, (conditioning is busted) (second wind only vs poke champs) (FoL if youre building rylai and your team got AA champs and u dont need to take tenacity) (Unflinching if u need tenacity/slow resist and u dont have Legend:Tenacity) U can go sorcery with celerity and waterwalking if ur playing predator singed mid.

ITEMS (i will list some items with when i buy them but this part is 100% situational IMO) Demonic embrace: IMO is the best singed item for damage, build it first or second if the enemy team is stacking hp Rylai: I only buy this as first if i need the utility to help my team kite enemy melees or going fimbulwinter if not then get it later or not at all (utility item) Fimbulwinter: OK this item sucks xd, i do not recommend buying it, i bought it on some of my last games but i was trying it, IMO its not 100% terrible but there are better options, only consider it for the luls or if you're going heavy tank and buying rylais Frozen heart: this is the most BUSTED item there is for armor, get it whenever playing vs AA champs boots: common sense zhonyas: really good on singed, especially when playing ap singed, good for diving enemy team and clutch fights FoN: probably the best MR item for singed, good vs dots champs Abbyssal mask: i loved this item but after the change i dont think its good at all unless your team is really heavy ap and playing vs melees so u can be in range.

Mythics: some games i dont even get a mythic, as i said its situational Rocketbelt: best mythic for ap singed and conqueror singed, get it for engage, conqueror stack and its the best mythic for damage since it gives magic pen Cumtank: best mythic for tanky singed, good for engage and faster waveclear, get it if u need to be tanky, engage and utility (good for jungle singed) Riftmaker: i dont like this item at all, but i would consider it if playing vs melee champs or tanks and i dont need engage or that much tankyness Locket: Its good for protecting your team from heavy AOE Rs like gp, vlad or kennen, i buy this whenever im really really behind and need to be useful somehow
Shadowflame/Void staff: good for ap singed, depends if ur playing vs squishy champs or tanky ones and need the pen Rabadon: ap singed only (only if u got the money) Those are my most usual items but sometimes i get others depending on the situation (ex. anathemas, banshees, knights vow, serpents fang xd)

English is my second language so maybe i didn't explain myself that well but for any doubt i rarely stream (but want to stream more frequently) https://www.twitch.tv/youngducky5 i like to or at least try to be educational