It is very important that parents teach gender identity from day one of their child's life. This will avoid gender confusion later in their child's life. Dressing a child appropriately for his or her gender from birth onwards and using the correct words and pronouns when you are addressing your child is crucial. Tell your child he is a boy like daddy or a girl like mommy.
As our sons and grandson grew and began understanding and using speech to communicate, I and my family would make a point to use their older male relatives as role models for them to aspire to be like.
For example: when we dressed them to go out in public we would tell them how good they looked - they were handsome like daddy, or poppaw, or their favorite uncle. When they accomplished a difficult task, we praised them for being strong or doing a good job - just like daddy, poppaw, or uncle.
Likewise, our daughter and granddaughter were told they were pretty like mommy, or mommaw, or their favorite aunt. They wore dresses or skirts or hose like mommy, etc. They did a good job just like mommy, mommaw, or aunt.
By regularly comparing your child to a favorite relative of the same gender and by allowing your child to spend regular quality time with relatives of the same gender as your child, by age 3 years old your child should have no trouble knowing and identifying with his or her own gender. Recently, my 38 month old grandson told me that he and his daddy are boys, and his sister and mother are girls. He also told one day as we were channel surfing, that he did not want to watch a certain cartoon because it was "for girls". It was a cartoon about fairies. lol!
Of course, children are curious and will frequently want to try something not usual or traditional for their gender. For example, a small boy may want to try on his mother's shoes. No harm done. It is all for fun. No big deal as long as he is made aware that those are "girl" shoes and he is a boy. If he wants to try on his sister's hair ribbon, no big deal. Let him see himself in a mirror and tell him little boys look much better without a ribbon because they want to grow up to be like daddy, or poppaw, or uncle. Then, give him one of his daddy's ball caps to wear so he can truly be like him. The key is encouragement and positive reinforcement. If your children are encouraged to feel good about what they are genetically, then they will never have any doubts about what they are, and they will not want to be anything else!
As children grow, they may develop interests that seem to be more for the opposite gender. Sometimes these children may begin to wish they were the opposite gender so they would feel more comfortable doing those things. As parents we need to encourage their interests while still assuring them that they can still do those things and be proud of the gender that they are. This was the case for a niece of mine a few years ago when she was about 13 years old. She has always been a "tom boy". Rough, tough. She is beautiful and feminine-looking with long blonde hair, a very pretty face, and a great body. Despite her "girly" looks, she has never liked playing with dolls much. She dresses plainly - jeans and t-shirts. Hardly any jewelry, and no make-up. She likes trucks, playing ball, hunting, etc. One day she said, "I wish I was a boy so I could play football." She wanted to play on her school's football team. I, along with her granny and aunt, assured her that she was what God had intended her to be, and she should be happy with herself for what she was. We also consoled her with the fact that being female should not be a hindrance to what she may want to do. She could still do "boy" things and yet be happy being a girl.
We never heard anymore gender complaints from my niece after that. I don't know if she ever tried out for her school's football team, but she did (still does) frequently play football with male friends and relatives. She has also brought down her first deer. Her feminine side has even managed to shine through a time or two. She was homecoming queen last year, and has been dating a guy for a couple of years now. She is no longer dissatisfied with what she was born to be.
The Bible says for parents to train up their children in the way they should go. We cannot leave it to chance, or peer pressure, or political correctness. That would only lead our children astray and make them confused.