The short version of working with young children:
1) Give them an area to explore.
2) Keep the session quick.
3) Know your route.
Starting with the first one and working from there, give these kids a place to explore. Kids are programmed to learn so they want to explore. If you give them something to explore they give you something to work with. Often, this is as simple as taking them someplace new or giving them a new take on an old place. In the case of these photos, this little lady is used to being behind that fence, not outside it – that’s why she’s pointing in the picture. It’s new to her so it feeds that curiosity.
Next, keep the session quick. Young kids tire out quick. When they get tired, they get frustrated. When they get frustrated, they get to crying. So, try to keep it shorter. How short? That is something you will have to gauge the kid on. Some can go longer and some need it done very quickly. Not to mention all the variables like time from the last nap, how recently they ate, and other things.
Finally, and this goes hand in hand with keeping the session quick but that is to know your route. Have a plan for where you are photographing your subject. You know you need to keep it quick, so what are 2 to 5 areas within a few seconds of each other in your immediate area? Have a plan for that so you can keep things quick but also keep things different with each step of the photo session.
Bonus tip: Get down to their eye level for the photos. Things will work out so much better that way.