Well, the year’s almost over. Which means, yes, holiday parties and stress eating. But it also means that 2016 and all its challenges and opportunities are just around the corner.

2015 was a fast-paced year for marketers. Personalization went from a nice add-on to something essential. Brands struggled to find effective ways to engage millennial consumers. Data privacy and people’s complex feelings about it became a significant issue. Thankfully, marketers had a lot of great new content this year to draw on: blog posts, guides and articles dishing out insights and provocative ideas about the ins-and-outs of digital marketing in all its forms.

We learned a lot. About design and writing. About creativity and the important lessons that chocolatiers and door-to-door vacuum salespeople can teach marketers. So we decided to share our favorites with you. Here they are, the best—in our considered, expert, just-re-read-a-ton-of-articles opinion—of what 2015 had to offer marketers:

Content marketing and social media

A lot of companies have turned their attention to content marketing in recent years, but few with as much radical honesty and transparency as Buffer. In “We’ve Lost Nearly Half Our Social Referral Traffic in the Last 12 Months,” Kevan Lee openly and unflinchingly dives into a major issue that Buffer’s content marketing team is struggling with—namely the collapse of its organic social referrals—and uses it to explore how marketing is changing and how marketers should respond.

Building a holistic mobile strategy

You can have the best customer outreach strategy in the business, but if it doesn’t fit together with the rest of your brand’s mobile marketing efforts, you’re going to miss out on opportunities for conversions, higher customer engagement, and stronger relationships with your audience. In “Are You Guilty of Committing One of These 27 Mobile Marketing Mistakes?” Mobile Marketing Engine’s Greg Hickman looks at mobile messaging, websites, checkout and more, identifying places where your brand’s mobile experience can work as a cohesive whole—or, alternately, alienate customers.

Creativity

All good marketing starts with an idea. Or, better yet, lots of them. But how do you come up with ideas—and what can you do to jumpstart the process? NewsCred’s Chase Neinken has your back. In his piece, “3 Creativity Tips For Content Marketers From Monty Python,” Neinken lays out how former Monty Python member and comic genius John Cleese discovered and nurtured his creative side, and explains how marketers can use the same approaches to overcome writer’s block and other creative roadblocks.

The limits of marketing

No marketer likes to focus on what they can’t do. But while effective marketing plays a major role in long-term business success, there are situations where marketing simply isn’t the answer to a brand’s most pressing issues. In “You don’t need a growth hacker,” Andrew Chen examines the retention and engagement challenges facing startups—and argues that, for most, a focus on marketing and growth should come later, after issues with product/market fit have been worked out.

Marketing writing

You know that your copy is missing something, but what? The Copybot’s Demian Farnworth thinks it might be nothing—literally nothing. In “How Web Writers Can Improve Their Copy with White Space,” he looks at how marketers can use negative space to spice up their writing and make a stronger impression.

Marketing design

While writing is an essential part of a successful marketing campaign, don’t forget about the important role that design plays in engaging customers. Brafton’s Ben Silverman has put together “Top graphic design trends for 2016: Usable, mobile, accessible,” to help keep marketers up to date on what’s current in digital design, including the new prominence of flat, dynamic design.

Mobile email marketing

Email has been a mainstay of digital marketing since before the rise of today’s mobile-first world. But with most email opens now happening on mobile devices, brands should be thinking about those mobile views before hitting “send.” In “3 Steps to Maximize Your Mobile Email Marketing,” RankLab’s Cynthia Johnson, writing forEntrepreneur.com, takes an in-depth look at mobile email and provides best practices for optimizing every aspect of the messages you send in this important channel.

Optimizing conversions

When it comes to convincing customers to convert, why not learn from someone who’s had experience making a much harder sell? In “What Being a Vacuum Cleaner Salesman Taught Me About Conversion Rate Optimization,”Unbounce’s Angus Lynch uses his in-person sales experience to help marketers learn how to connect with, engage, and persuade their audience—without alienating the people they’re trying to reach.

Getting customers’ attention

There’s more to marketing than just catching potential customers’ eyes—but that’s an important starting point. In “The ‘Coffee & Truffles Standard’: Marketing Lessons Via Savvy San Fran Chocolatier,” Aimclear’s Marty Weintraub learns how to get the attention of potential customers and how to nurture those prospects from awareness to conversion, all with a little help from San Francisco’s XOX Truffles chocolate shop.

Customer data collection

Before you can properly target or personalize the marketing messages you send, you need customer data to support those efforts. In “The App Marketer’s Guide to Social Logins,” Sparkpage’s Emma O’Neill looks at how using a social login for your app can make it easier to collect the kind of audience data that underlies strong customer/brand relationships. The piece also explores possible downsides and discusses real-life brands taking advantage of this login option.

Staying on top of the hot new thing

One major challenge that marketers face today is the ongoing proliferation of platforms and channels that can be used to get the word out about their brand. Get in early with the right one and you have a major competitive advantage; but waste your time with too many that don’t pan out and you’ll find yourself falling behind. In “Why Your Business Should Be Ready for New Social Media Platforms,” Sprout Social’s Dominique Jackson explains how brands can identify new platforms that are likely to benefit their marketing goals and highlights a few up-and-comers to keep your eye on.