Don't be prejudiced or biased. Every country, religion, or racial group has its own beliefs. Like them, you have your own beliefs, so respect them for theirs.
You certainly do not have to agree with every event and decision made in your country's history to love your country. Consider how the country recovered from mistakes, as well as its ideology as described in some guiding document (such as a constitution). Although such principles are not absolute, reflect on whether these precepts are conducive to a government you think would act with its citizens — and humanity's — best interests at heart.
Abusing your country or taking advantage of any of its systems or programs is not a good way to show your love. Such corrupt action goes against the goodwill that should be at the core of patriotism.
Encourage children to love their country so they will have respect someday as a citizen. This is the best way to set a positive example. As children grow older, explain to them why you feel they should hold their country in high regard. Remember that blind patriotism can be dangerous. Encourage your children to use their minds.