The most important thing is: Love & understanding.  It is of utmost importance to create some mechanism to overcome: misunderstandings / fights / difficulties

Marriage includes sex.  The "back-to-back" position is bet attempted by the exceptionally well endowed or those who have decided not to speak to each other.  That brings a number of practices to mind:

1.  Tell your partner what REALLY turns you on.
2.  Call the emergency room when your partner realizes you weren't kidding.

Okay, rookies at sex need to realize that the longer you have been sexually active in marriage, the less inhibited you are:

1.  Invite your partner to a party of people who enjoy what you do.
2.  Call the emergency room when your partner realizes that you weren't kidding.

Young people have yet to realize what we old professionals do to slake the unbelievable lusts of our sexual partners -- mainly because we old professionals are less inhibited than you inexpert newlyweds.

1.  Tell your partner what your late spouse and you did.
2.  Spend the next three days calming your new bride, or:
3.  If you are over 45, spend the next three days trying in vain to awaken her from the boredom coma, and she will then educate you.

Give and take lovingly and with passion.

No passion no marriage.

Share, love, respect, revere, give, forgive, and energize, your partner.  Whatever you and your spouse would want in a second spouse, be that way.

I do agree that communication and love for each other is the key for marriage to succeed.

Love. Intimacy. Respect. Personal Space.