We rebuild the page closest to your sale and run it against the page you have now, on your own live traffic. The scoreboard is revenue per visitor, not a dashboard metric.
Usually the product page, because that is where the money is decided. Layout, copy and offer rebuilt as one piece rather than patched with small tweaks.
Old page and new page live at the same time, so seasonality and ad spend hit both equally. The test decides, not an opinion in a deck.
Two or three tests a month after the rebuild, each one built on what the last test told us about your buyers.
Fewer opinions, more tested changes: every rebuild is judged on your own traffic, against the page you are running today.