So how should Galactus be done in the MCU?

I'd prefer something along the lines of Kronos from Clash of the Titans (or was it Wrath of the titans?). Someone humongous and semi-wreathed in smoke, lightning, fire, etc. So you never get a clear full look of him but get shots here and there. A shot of his face here, an arm there, a torso for a split second, etc.

Because I feel like just showing a purple-armored giant with robot horns won't translate well to film. 

He shouldnt be shown much. The horror of his size and aura should be implied kinda like the Cloverfield monster or Godzilla 2016.

He has those RDJ heel lifts in his space boots.

He should be portrayed in a deadly serious manner like with Thanos. Really, Galactus is the logical successor in terms of cosmic threats to the MCU.  He should be gigantic in stature (like Godzilla sized) and retain his godlike power. The MCU is at the point where they can depict any character onscreen as they wish.

This reminds me of the last Thanksgiving my ex-wife and I shared with my family. It's a common thing in my family that I say I'm 6'3" when I'm actually 6'2.5", my brother says he's 6' when he's just over 5'11". My sis says she needs to lose 5lbs when we all know it's probably closer to 30, My aunt says she's 10 years younger than she is. (even when people know she's a twin and my mom says the correct age). So during the Thanksgiving games I can't remember who went up to hike the ball on 4th down. I said if they hike the ball I got a 12" cock. They hiked the ball. I looked around and said well a foot just got 30% shorter. My ex with out missing a beat said "40% honey. No wait forgot about the thing. 30% shorter." This is not the reason we broke up.   

edit: I don't know what the % should actually be just the fact she played of the running gag was what made everyone laugh. Lets be honest I know the % and the foot got a lot smaller.

To be honest they need to ratchet down stakes for a while after Avengers 4. You can't artificially push some one higher than Thanos and the Infinity Stones or it makes Him and the snap look weaker in hindsight. And there isn't a lot out their that could be potentially as high of a risk than trillions perishing in a snap. (Celestials/Eternals  I guess). Galactus could be a localized threat just to the Kree, Earth, or several systems, but we don't need the whole Universe threatened again. Honestly I want to see the Avengers vs. Dr. Doom for a while. Not him in every solo, but him pushing the chess pieces on the board.