There is no fixed trade list. Your price book is your tag system.
What is built in
Window and Door are built in and use the native size dialogs. Pin and View are markup only, with no quantity or price. Every other tag is a category you create.
Make a category
Open Settings, Selling, Price book and tap + on a category header (or New Category). A category is only a name and an icon. Categories belong to a market, so a second market can have its own set.
The measurement sits on each product: area (SF), linear (LF) or count (EA), plus supplier units such as squares, bundles or square yards. One folder can mix shingles by the square foot, ridge cap by the foot and pipe boots each. Give each product a waste factor so the order quantity already includes it.
From tag to estimate
Choose a category in the tag palette (Windows and Doors and your categories appear together), place the tag and open it to enter the area, length or count. The product chooser shows only the price book items in that category, and the live estimate value updates as you tag.
Takeoff groups every line by category, in its unit, with waste added, and shows a readiness summary (quoted, priced, ballpark, unpriced). A line without a product has a one-tap Choose Product that prices every tag behind it. Create Estimate from Takeoff turns each category group into a priced line, ready to send as a proposal.
Pro tip: Name categories the way your supplier orders, so the takeoff reads like the order.