Costs first, because costs are forever. On the order-book side, Coinbase's Advanced experience is still one of the clearest default upgrades for most people who graduate from beginner mode. Coinbase's help documentation describes Advanced Trading as using volume-based pricing with fees up to 0.4% maker and 0.6% taker, depending on your tier.
Kraken is even more explicit about the split between simple and pro-style trading: its fee schedule shows a 1% fee on instant and recurring trades and a 1.5% fee on custom orders, while Kraken Pro spot trading uses maker-taker tiers that start at 0.40% maker and 0.80% taker for the entry tier.
Gemini's ActiveTrader schedule is also transparent and very institutional in how it's presented; the base spot tier shows 0.600% maker and 1.200% taker, with lower tiers for higher volume or balance.
That brings up the concept most traders misuse: maker vs taker fees. Maker means your order adds liquidity by resting on the book, typically a limit order that doesn't fill immediately. Taker means you remove liquidity by filling right away, such as market orders and aggressively priced limits.
In practice, if you're cost-sensitive, you'll often accept slightly less certainty on entry in exchange for lower maker fees — provided the platform's spreads and fill quality don't erase the savings. This is where execution quality becomes the second filter that most best exchange lists quietly fail readers by being vague.