Anything associated with a more exclusive and more expensive lifestyle is a no-brainer, of course. Organic, locally-sourced food is de rigeur. Sustainable fashion. How could you NOT? These ethics make life more fun. Also, when your lunch/shirt is sustainable, you can pass it off as virtuous discipline, but if it isn't, it's not really a big deal.
Solar panels are controversial. They're expensive, but they're also unattractive, and they're pretty nerdy, and even worse, they're technology. It's very hard for them not to be declasse. You can thread the needle with these if they're unobtrusive and you make it very clear that you never personally touch or operate them yourself. But there are so many other braggable efficiencies you can add to your house (brise-soleil made from sustainable wood!) that it probably isn't worth the effort.
Vegetarianism and veganism are out, because duh, buzzkill (how do you even brunch?) but saying you eat less meat is in, as long as you're eating some kind of artisanal, locally-sourced charcuterie when you say it.
Driving is in, of course. The alternatives are too much work, and it's very hard to make them look cool. So driving is an important thing to defend.
Cycling is the most visible threat to the virtuousness of driving. It's eminently feasible, unless you're elderly or differently-abled, and it's sweaty and very very hard to look cool (congrats if you look cool, and please fuck off) so it needs to be stigmatized. Luckily, you can lean on the stereotype of cyclists being (ominous voice) affluent white males who are privileged to have disposable income to throw away on expensive toys. Whew. Thanks to that, there's zero stigma for an adult, able-bodied person to spend twenty minutes idling their car a mile and a half home during rush hour. The alternative is supporting a sexist, ableist, and otherwise elitist solution, presumably at the expense of more equitable ones.
Same thing with scooters, except they're worse because they're tech. Techbros did this! Your car will always be in the street where it never blocks the path of the differently abled, and by contributing to traffic you're ratcheting up the pressure on that darned city government to provide equitable, egalitarian mass transit which when it arrives will make your 1.5 mile drive to work so much easier. An effective response to climate change has to be collective, and individualistic solutions just distract and dissipate energy from collective ones. (Don't worry. Nobody will use this argument to undermine your artisinal, locally-sourced charcuterie.)
You might think riding the bus would be even worse than cycling, but in reality, it's not really a threat, because it's so ostentatiously hair-shirt. (Rule #1: we're supposed to be enjoying ourselves.) Also, when someone else talks about riding the bus, it gives you a great excuse to show off your knowledge of transit issues when you explain how you can't ride the bus because service coverage is so awful and we really need to do something about this! They might be trying to shame you, but they're really doing you a favor. Because come on, the bus? Ha.
Taking your batteries and fluorescent bulbs to the hazardous household waste facility instead of putting them in the garbage? Nobody is going to bring that up unless they actually do it. Don't hold your breath.
Xeriscaping... this one sucks. It's impossible to criticize it, and worst of all, every time someone looks at your grass and asks if you've thought about it, you have to admit that you're renting and you're afraid that if you remind your landlord that you exist they'll raise your rent and price you out of the neighborhood.