Kiss and hug him always
Yes, you really need to trust me on this. If you can kiss and hug him dedicatedly he will be exceedingly happy. He will appreciate it.Do this always. He will love it. If you can kiss him in public; it will yield multiple results.
Spend some quality time with him
Despite your busy schedules, find time to relax with him. If you are a working class, then ensure you find time and go for shopping with him during weekends, or hang out with him during your free time. Your boyfriend deserves every love, care and affection you can ever get from you.
While spending time with him, engage him with cute stories and fond memories. Let everything you do be geared towards making him happy. He deserves to be celebrated by you. No matter how things are, ensure you are poised to make him happy.