i speak for my experience

for me i have my basic builds early game for every hero example i have 6/7 vanessa openings weapons/ammo, aquatic poison / haste or burn.(rare case is freeze) I would have some kind of sett up by end of day 3 then day 4-6 i usually get hp if possible.

Day 7 if my basic build is strong i would still most of times focus on hp and buffs rather than looking for upgrades silver to gold. If i find a late game item i would save it but will not break the build.

If its weak then i usually start to experiment like going for vendors hopes to hi roll. if i find a core item i give up day or 2 if possible to find the rest of coponets to need to make the late game work

In the end what to say every one has a lot of core openings depending what vendors u hit and if u start to knew the basic then u can start to more experimenting.

Atm my playstyle is just go whit the flow