I use those take-n-toss cups with a straw- typically do almond milk, frozen peaches and berries, fresh berries, and spinach. The other day DS said, "ooh, I got a leaf" (through the straw), ha ha...

Immersion blender works great, but frozen fruit has to be defrosted first.

Mango, banana, coconut milk and cooked cauliflower (yes!) tastes like a piña colada.

Please vary up the spinach--they contain oxalates so when eaten daily or in high amounts, can cause issues with calcium levels. So mix up your greens--Swiss chard, kale, beet greens, mâché, even dark romaine lettuce.

Also, since spinach contains fat-soluble vitamins, it's important to consume healthy fats (coconut, avocado, almond butter, etc) in the same meal to maximize absorption of the vitamins in spinach.

Target has some insulated cups with fat straws (and stoppers so they can't be pulled out) and lids. I like the fat straws since they don't get clogged easily. (I can't find them on the website or I'd link.) I've seen similar cups all over the place (grocery stores, drugstores, etc.) although not as much now that it's winter.

We didn't want to spring for a Vitamix just for smoothies so we got a Breville Hemisphere partly based on Cooks' Illustrated reviews and partly after seeing one that a friend got. It's been much better than our old Waring bar blender, which might not be saying much, but we like it a lot thus far.

I use those to-go coffee cups with lids. The seeds don't block the hole.