The biggest excuse I hear from non-marketers about marketing is that they don't have time to market their business. They know they need marketing to be successful, but they don't have the time or know what to do even if they had the time.

While it's always ideal to have some marketing skills, there are plenty of simple marketing tips for small businesses you can tackle even if you only have 15-minutes a day. From old-school marketing tools to modern-day marketing tactics, here are 15 marketing ideas you can do in just 15 minutes.

1. Draft copy for your email newsletter.

Most people don't send out regular email newsletters because sitting down and writing one takes time. But if you just draft it, you're ahead of the game. You can absolutely draft a decent outline of what you want to write in 15 minutes.

2. Build your email list.

I'm an advocate of building your email list because unlike building up your social media accounts that can disappear overnight, your email list is something you own. We don't own our Facebook fans or Twitter followers so if you rely on social media to market your business at the expense of building your own email list, it's a risky move. Take 15 minutes a day to invite people to join your email list. It's 15 minutes of time well-spent.

3. Create an editorial calendar for your email newsletter and blog posts.

A former supervisor used to drill in my head: Plan your work, work your plan. What gets planned, gets done, so take a few minutes each day reviewing your editorial calendar and what you plan to write in your next newsletter and for your blog. You can always tweak it throughout the year, but having clear deadlines of when you want that newsletter to go out or when that blog post needs to be up will help make it happen.

4. Find a place to submit a guest blog post.

Locate a complementary business where your guest blog post will market you to new customers or clients.

5. Make friends with a reporter.

What media does your customer consume regularly? Is it the local daily newspaper or a trade journal? Does your industry have a great podcast host? What kind of story can you share that would be of interest to your customers? Reach out to that reporter and introduce yourself.

6. Listen to a podcast about marketing.

The best marketing ideas come from the most unexpected places. Podcasts are an easy way to learn of new ideas and how you can make them work for you.

7. Take a stand for what you believe in.

Millennials and Generation Z are demanding transparency and want to know where businesses stand when it comes to certain causes. Is there something you feel your business can stand for and show your support? Jot down some ideas and hold a mini focus group with customers to see how they feel.

8. Find a place to submit an OpEd.

Have something you want to say? Consider sharing an Opinion piece in a media outlet.

9. Read a book.

Pick up fellow contributor Damon Brown's The Ultimate Bite-Sized Entrepreneur Trilogy where he provides ideas, including some good marketing ones, in quick reads.

10. Ask a customer for a testimonial.

Ask just one customer if they'd be able to write a testimonial you can share on your website, brochures, LinkedIn, or email newsletter.

11. Ask a customer to refer business to you.

Our best customers are often our best fans. Ask if they feel your business or service might be of interest to someone they know and ask for a referral. It's amazing how much new business I've secured simply because my current clients knew I had time to work with new clients and they were all too happy to recommend me.

12. Follow-up with former colleagues, clients or customers.

People move jobs and customers come and go for various reasons but it's worth checking-in with former colleagues, clients and customers because you never know if now is the right time to work together again.

13. Create a video.

Create a quick 15 or 30-second video of what's happening in your business right now and post it on a social media platform.

14. Do a brain dump.

You may not be able to get every marketing idea you want done, but simply getting it out of your head and onto paper helps you see what has merit and what needs to be discarded.

15. Push along plans for that one thing.

Remember that one thing you wanted to do this year? Whatever it is, do one thing today to help move that idea forward today.