Just like trying to get fit or eat more healthily, developing your vocabulary is all about forming a habit. The key to being successful is consistency and perseverance - and, crucially, learning “little and often”.
Time and time again, research has shown that the most successful way to learn vocabulary in any language is to tackle it a few words at a time, as regularly as possible. Indeed, a number of studies have shown that this bite-sized approach is significantly more effective than attempting to learn a larger number of words every now and then. , 
How much more effective? One study found that bite-sized word learning is as much as 90% more effective than cramming, while another found that kids who learned words little and often were 35% more likely to remember them. , 
One theory behind the considerable benefits of the bite-sized approach is that words learned in this way are more likely to be stored in the brain’s long-term memory, meaning you can retrieve them again and again. If you try to cram, meanwhile, new words are unlikely to make it past your working memory - the cognitive system responsible for holding onto the kind of information that you only need to access temporarily.
In this way, developing your vocabulary requires a similar approach to trying to get fit or eat more healthily - the occasional salad or trip to the gym isn’t enough; you need to make it a habit. The key to being successful is consistency and perseverance - and, crucially, learning “little and often”.
Whether it’s one word at breakfast every day or a couple on the way home from school, if it’s fun, kids will want to keep it up.
Of course, habits are much easier to form if they’re enjoyable too. Research has shown that a particularly effective way to create a sustainable habit is to laugh while you’re doing it. That’s because laughter makes your brain release dopamine - the pleasure chemical that you’re also rewarded with when you eat chocolate or fall in love. As well as activating your brain’s long-term memory, dopamine is something that you always want more of - meaning that you’ll want to trigger it again and again. This makes humor-based learning extremely motivating, and perfect for helping form a habit. 
All of this is why we at Mrs Wordsmith work so hard to ensure that the illustrations in our Word a Day books really make kids laugh. Not only do they help kids understand what words mean, they make kids want to learn them. Whether it’s one word at breakfast every day or a couple on the way home from school, if it’s fun, kids will want to keep it up. And as we’ve seen, little and often is the key to success!
- Marulis, L. & Neuman, S. 2010. ‘The Effects of Vocabulary Intervention on Young Children’s Word Learning: A Meta-Analysis’. Review of Educational Research 80(3):300 - 335.
- Smith, T. (2008). Teaching Vocabulary Expeditiously: Three Keys to Improving Vocabulary Instruction. The English Journal, 97(4), 20-25.
- Kornell, N. (2009), Optimising learning using flashcards: Spacing is more effective than cramming. Appl. Cognit. Psychol., 23, 1297-1317.
- Bloom, K. C., and T. J. Shuell. (1981). “Effects of Massed and Distributed Practice on the Learning and Retention of Second-Language Vocabulary.” Journal of Educational Research 74 (4): 245– 248.
- Wise, R. (2004) Dopamine, learning and motivation. Nature Reviews Neuroscience, 5, 483-494.