Dropping off a young child at day care or preschool can be rough. There may be protests and wailing. Your kid may latch onto your leg for dear life. When my daughter started going to day care when she was one and a half, she cried every day for the first six weeks. The teachers were great, and I knew she was safe and cared for, but I ached seeing her so sad.
Many day care directors recommend the "rip off the Band-Aid" method of separation. Make the drop-off quick, and be confident as you leave. If you're confident, they will be confident... eventually. Don't linger and try to help them adjust ("Look at all the nice friends here!") -- it only makes the transition harder. And don't sneak out when they're not looking. That's just mean.
A goodbye ritual can also help. On a Reddit thread about dealing with day care drop-off drama, one parent wrote that their day care uses a "magic trick that works like a charm". The school makes a game out of pushing Mummy or Daddy out the door. If a kid is sad, someone will ask, "Should we push Mummy out the door?" and if the answer is yes, all the children will gather to help shove mama out. Lori Mihalich-Levin of Working Mums Against Guilt started using the tactic with her three-year-old son after her husband raved about how well it worked:
The big push out the door started as a bit of a game between my son and his daddy, but it quickly became an important part of the day care drop off routine for the entire family. There is something about little hands on my butt pushing me out the door that makes me smile every time. The teachers crack up watching it, so it lightens the mood all around. And my youngest sometimes even recruits his toddler friends to help, and they shout "Teamwork!" while giving us the big push.
As Mihalich-Levin mentions, rituals give kids a sense of predictability and stability. However, if you choose one that you can do alone with your child -- say, three hugs, three kisses and high-five -- it's best to do it before you get out of the car. When it's drop-off time, remember: Band-Aid. Go.