The Gottman's have written an excellent book some years ago for couples who are about to have, or have had, their first baby - And Baby Makes Three. This is the official book of their Bringing Baby Home Program for which there are also additional resources such as a workbook and card decks available on their website, plus a transition to parenthood webinar.
And Baby Makes Three includes a six-step plan for preserving relationship intimacy and rekindling romance - and based on their research also includes 10 secrets of couples whose post-baby sex life is going well. While all of these pointers are spot-on tips for couples with children, many also apply to childless couples leading busy lives.
10 SECRETS OF COUPLES WHOSE SEX LIFE IS GOING WELL
Accept that things have changed since the baby arrived
Ask each other for sex
Talk about what feels good sexually, and how to make it better
Continue nonsexual affection, especially touch
Realise that in most cases, he's a microwave and she's a Dutch oven
Accept that quickies are as important as gourmet sex
Accept masturbation, and continue to have oral sex (if you've always liked it)
Share your sexual fantasies
Discuss your innermost feelings and don't avoid conflict
Prioritise gourmet sex and make time for it.
They recommend looking through the list of ten items and picking one issue to discuss with your partner. Then both talk about what changes you would like to see in this area of your sex life. Be gentle.
Disclaimer: This post is for informational and educational purposes only. It should not be taken as counselling/therapy advice or used as a substitute for such. You should always speak to your own counsellor.