I think you can start with the landscaping and making sure that the plant material is not overgrown and is highlighting the features of the house. Its hard to see but the garage door looks like its out of character with the rest of the house (especially the colour).
And the front door and sidelights could be modernized to something more in keeping with the style of the house. Hope that helps!

I think I'd rework the entry to accommodate a huge pivoting front door, and perhaps replicate the door style in a custom gate between the stone walls. You could use metal or wood, perhaps wood for the door and metal in the same style for the gate. Paint the garage door to match the other side, or if possible, move the garage door to the side and match the facade on both sides of the entry.

the door and side lights are completely wrong.. start with changing those!
I like the horizontal ideas above.. you could do that detail with some doors like these

http://www.etodoors.com/shop/product/259

Agree with all suggestions above! Love the house...going to be a real showcase when you are done!

I'm not sure where you live but it looks somewhere warm. Usually grasses and succulents can help add color and shape to a residence.

Agree that the front door and side lights are totally wrong. There are a lot of mid century modern replacement doors out there, so I would start by searching Houzz.

JUST the doors and landscaping. That is a great MCM exterior.

Agree that the doors/sidelights were not the best choice for the architecture. I would not be too quick to change the other elements yet; its a pretty great MCM design. Think first about embracing it. Maximize it as it is in terms of paint color changes (like making the squares on the gates pop with an accent color). Taking the color palette on the house in a more mid century modern direction would go a long way. Ditto on the garage door: a flat panel door--with no windows, and no raised panels--and painted to match the house color so it disappears into the wall, rather than tries to be a feature, might be a better look. Can you post a pic of the stonework? That should be your guide to picking a MCM palette to replace the tuscan color scheme on the house now.

Just as an 'exercise' in changing the lenses in the glasses you view the house through, imagine the house done "Mondrian"... (google mondrian) Move the 2 potted trees (or take a pic and photoshop them out) in order to see the entry through fresh eyes again.

You're getting some nice advice. Definitely MCM leanings. Depending on your budget, I would consider powder coating your existing gate, making the frame black and making the random plates open with a very thin border--good for contrast in identifying the entry as such. Consider, if bldg. dept allows, a metal/wood trellis (matching any other natural wood, such as a new garage door?) over the entry gate, that is illuminated with recessed cable fixtures. Where the gated entry is, you could remove the existing siding (stucco?) and replace it with HardiePanel (3rd pic). I would paint the house body a brown that has more red than yellow and a shade or two darker, Paint the beam ends the same color as the fascia, or remove the paint and leave them natural. Definitely, as mentioned earlier, I believe you should replace the garage door and the entry door to add some period punch. Consider a wood slat door, natural, and for the entry door, something a little funky. I leave the landscape advice to my betters, other than to say, if you had matching trees equally spaced on both sides of the entry gate, with landscaping uplights, that would look great at night, especially in concert with a lit trellis atop the entry gate. It will compliment what you do with the rest of the home very nicely. Update your sconces, if not already, and black. Good Houzzing.