Be carefull not to mistake ISFp with ESFp. They can be very similar at first. Similar smile, look in the eyes, good taste at clothing. But once you will start talking to her, you will understand who she is. Make multimeaningful jokes, be sarcastic, show your logical skills. ISFp loves when someone suddenly comes up with an interesting critics to something old. Like why their workingplace needs to be reformed. ESFP on the other hand, needs a distance. You will admire him or her. Find that person funny. He or she is like a hero for you. But once you two get more close, you will see that ESFp is too powerfull and needs to get what he or she wants. You are also helpless to suport that person with advice or doings, because you can't give what is wanted. Can't give explanetions to it's problems, can't use your intuition to guide. Close distance will suck you out of your energy. Only way to get along with ESFP is in a company of many people, where some of them are in better socionics relationships with you. I have found the triad ENTp-INFp-ESFp working well.

One thing with ISFP what you should know is that they sometimes annoy you by asking all sort of explanations. Like why you don't get along with someone. What does this or that term mean. This usually happens with ISFps who haven't developed their skill to think independently. Older ISFps usually are able to answer alone to some of the questions they want to understand. Though they still think that everyting should be discussed through by detail before she can make her choise.