The first step makes sure you are both willing to make it work say you want to go to snowboarding tonight but your partner wants to go dancing be ready to change to your plans sometimes to match your partner's plans.
Step 2 Be honest many people tell lies to try and make it work such as say" I love you " when they are not in fact in love never lie about this simple you are digging hole ready for you to fall down since it's very likely if you lie about it your partner will find out sooner or later. Don't try and put on false personality say you hate for example pop music, but your partner loves it be honest since if you don't, you can have problems after problems relating to this such as always wants you to go to a pop concert with you.
Step three plan what you want in the relationship it could be anything from having marriage for life to severe connection and see if the person is what you want in a partner say you want a romantic, charming, friendly, busy person then check if your current partner has that if he or she does have that get more connected to them and preparing for getting more severe with them.
Move in together together this is the best way to find out if you will workout well or not but I would recommend unless you sure it's will work out more to home which is not your or her if possible the reason I say this you might find out hanging short term you both workout tremendous but long time together you don't like your partner being you such as you might find the person annoying, unclean, get in way with your problems or a range of other things
Plan for actual marriage you need to make sure you are both willing to agree on the same location for the marriage location since many different families have rules for how marriage has to complete such as my one believes in marrying in are home area of Inverness or Urquhart castle meaning a suitable person would need to be willing to go to the two different places to complete the marriage rights which someone might not agree if that's so then you would need to try and convince the other to go with your wishes if possible .
Step 6 Marriage life
You need to both be willing to do things to help the relationship stay strong which keep things interesting such as one a month go on holiday, Tennis lessons, go to sports, travel, Romantic meals, go to beaches, go to comedy clubs.
Step 6 Having kids
You must both make sure you ready for this such have the financial levels needed to raise a kid so if you little money or big best to sort out your money problems before you have them. Make sure both of you have enough time for them since say you work 50 hours a week could you cut down to 40 hours, so you get your kids 10 hours longer a week and be willing to see them as much as possible while working with your wife or husband to make both your relationships workout well.