The children learn from the life itself and when we put them in the school they learn with all the children. But unschooling is not a very popular method of schooling as most parents fear that their child will not learn what the others learn in school. Basically, unschooling is the solution for homeschooling and it does not have a set pattern and the children are allowed to decide what they want to learn about. The unschooling also has some set patterns and if you adhere to that you will be doing the right thing by your child.
Find out what the child is more interested in and teach her the thing he/she is more interested in. let her/him select the topic he/she wants to learn like if the child is interested in learning about the flowers teach her all the aspects of the flower, the names of the various flowers, their functions and show the flowers. This process will go on till he/she does not get bored with the subject or at least for a month or a day or weeks. The child has a say in the matter how much she/he needs to learn.
The same subject you can make it interesting by showing them books, videos magazines, any games available in this subject, the puzzles. Take them for a field trip or visit a museum or park and show them which will be very interesting for a child and they will have a renewed interest in the subject.
Search for the learning in the day to day life if you are teaching about vegetables you can teach them about nutrients, the vitamins and you can broaden their learning process.