There are some who are said to take special care of certain things. However, I think it is better to read their lives, celebrate their feast days, and love them. Throughout life, you will develop relationships with certain saints--you will know their lives, sing their hymns, pray to them frequently, etc. and they will be part of your extended, heavenly family. To me, that's more effective than looking at a list and matching Saint A to Cause B, but this has worked for others. The more you read the lvies of the saints, the more you will be able to find to which ones God has entrusted you.