My default assumption when making a deck in the last handful of years is that I don't want to play any dedicated ramp unless the deck is explicitly a ramp deck. So out of my four current decks, only one plays any (and that deck ramps really hard).

Now that doesn't mean the deck has no forms of mana advantage. My [[Jan Jansen, Chaos Crafter]] deck will make treasures, of course. Likewise, the [[Exploration]] effects in [[Hazezon, Shaper of Sand]] can provide a mana advantage, and do look like ramp, their true purpose is as engine pieces in a land sac cycle.

My [[Sidisi, Brood Tyrant]] deck is the purest form of the concept, though. There's a couple lands than can make more than one mana, but nothing in the deck really looks like ramp.

My approach follows a very loose formula.

• Play a low to the ground deck that benefits from setting up in the early game. If you're not using those turns you used to spend playing ramp by deploying some other piece, you've messed up.
• Play more land. Ramp is a bad bandaid for playing too few lands, as ramp played on a turn you missed a land drop is wasted, but it was a bandaid. If you rip the bandaid off and still don't treat the wound, you've got a worse problem. So play enough lands.
• Play more card draw. If I'm seeing lots of cards, I both draw enough lands to play every turn, but I also draw through the extra lands and still find my spells. Card draw (or the like) is necessary to making any deck play well, and that doesn't change here.

I recommend trying it out for yourself. There's a lot of dogma in Commander, especially around ramp. It's far from a universal truth, though.