Dash at your opponent, short hop, on your descent Cypher, once you have upward momentum while low to the ground cancel into Nair, the upward momentum means you'll hover for a bit allowing you to get off multiple hits of the Nair, your opponent has to wait in shield or eat foot. L-cancel the landing, immediately go into a crouch and try to shield poke them, they're unlikely to expect it, their shield will have worn down a bit due to having to have been held out during your Nair. If you think they'll try to shieldgrab your landing, their grab will probably whiff on your crouching hitbox anyway. If they drop their shield to attack, again, low profile, you'll crouch cancel it, you can poke their feet with your quick crouch attack.
Of course, this assumes you're given free range to approach a standing opponent who won't interrupt your approach and will react defensively. React as appropriate, if they dash toward as you shorthop in, feel free to Nair, or, something I've found useful, triangle dash down and back, suddenly they're approaching into you instead of the other way around, and Snake has much better options in that situation.
Specifically timed, cypher float aerials though are gimmicky, don't rely on them too much. Ultimately what you need to do is approach to mid/close range, and apply pressure, you aren't Fox sex kicking your way in at high speeds, what you want to do is get to an effective range and play footsies, you've got a lot of powerful tools to punish, a lot of great close quarter tools once the gap is breached, so bait them out and punish. One thing I like to do is short hop towards them, Nikita, cancel as soon as possible. They're extremely tempted to punish your helplessness and you're moving towards them at mid/close range, but the Nikita should cover your trajectory and with the drop and how fast it cancels, it's surprisingly difficult to punish- use that to your advantage.
Again, you don't approach, you zone if you can, play the footsies game, bait them out and punish hard.
