Hello R.,
What has worked for me with my daughter was to teach her how to fall asleep on her own. The other important thing is to make sure the baby is warm dressed, especially their feet; warm fluffy socks or warm and comfy booties. Sometimes babies wake up at night from simply being cold and they don't know how to fall back to sleep on their own. Here is an article I have saved for you;
Step 1 When your child calls out for you or starts crying after you have put him to bed, wait for a minute or two, then go to him but do not turn on the light in his room or take him out of the crib.
Step 2 Speak quietly to your child and reassure him that you are there if he needs you. But also be firm about the fact that it is time for sleeping and not for talking. Then leave the room while your child is still awake.
Step 3 The next time he cries (which may be immediately after you leave), wait a minute longer than you did the first time, then repeat the process.
Continue in this fashion, letting your child cry a little bit longer each time before you go to him. Speak to him briefly, and leave the bedroom while he is still awake. On the second night, wait a little longer than you did the first time on the first night before going in to your child, then repeat the pattern. By the second or third night, you may well find that your child is already going to sleep sooner.
When your child wakes in the night and cries for you, use the same technique. Let him cry for four or five minutes, then go to him, reassure him that you are there, and leave. Return at lengthening intervals as necessary. Eventually, your child will learn to put himself to sleep without your help. The associations that he once may have needed-having his back stroked or a lullaby sung to him until he fell asleep-will gradually be replaced with others: Being in his crib with his special toy or blanket, for example, will be enough.
You can rest assured that a little bit of crying will not hurt your child. In the long run, allowing him to cry for a few minutes at a time for a few nights will be far more beneficial to him (and to the rest of the family) than allowing a poor sleeping pattern to persist. Using this method, success can come remarkably quickly, almost always within a couple of weeks once you start it, and often within just three or four nights.