Yo, I gotta try that gp build, looks legit
Here's what I usually do:
If it's going to be a safer lane (you can just richard around behind your tower most of the match) Start cull
If you're ahead/even/not entirely behind
Begin progress on the god's instrument titanic hydra
If you're behind
Go for a shroud into frozen/gauntlet/deadman's plate (Pick. Sheen + Damage or more tank and mobility) if they're AD
Otherwise, go for a cowl into visage (ORANGE HEALS FOR DAYS)
Go for a lucidity in there somewhere.
Once you get Titanic Hydra, you can instant clear all casters. With sheen/iceborn you can pretty much one-shot anywave. This is part of why I love the build, you push like a loving crazy man. Moreso, you get a stuffton of SS, on most matches I get an early 2nd upgrade, and can hit 3rd if I keep going.
If you have the holy quadrangle of items (Titanic, Lucidty, Iceborn/Frozen <3, Visage),
you can pretty much go whatever the hell you feel like from there since oranges are up every 8 seconds and heal for 180 + 18% missing health making you as loving unkillable as a kiting darius. except with cc cleanse. and oranges. and parrrleys.
This is why I usually go for gage next. You don't loving go down without a fight, you have a goddamn second health bar + forgetton more oranges and have 200+ ad at this stage, scaling damage off of HP, healing HP, DEALING MASSIVE AMOUNTS OF HP. Better yet, you can auto reset with titanic (And if you just ate an orange, combo in a spellblade) and just string auto attacks together.
6th Item is then entirely situational.
If they're AP heavy, go for a Maw/Veil/banner idc
If they're AD heavy, go for a deadmans (if you don't have it from earlier) or omen or whatever's the best against their weird comp
If they're squishy as hell and you're super ahead, forget it just build that new item that does execute damage and ruin everyone's day by applying it on a Q, or a ghostblade and just laugh as you run fast and auto fast.
If they're all of the above, go for a gg ez'rot and laugh as you push them into another dimension
EDIT:
tl;dr
Titanic -> Lucidity -> Iceborn (if AD top)/Visage (if AP top) -> Iceborn(if went Visage)/Visage(if went Iceborn) -> Gage -> whatever fills in your gap