Use things around the house that they already know and love! : My son has a HUGE adoration for his Thomas Trains... he can tell you every single trains name, number and color. When we started working on recognizing numbers and colors, I tried to use posters, games, workbooks, etc that would help him learn to recognize them... all to no avail! One day, we were playing with his trains, and HE asked me what number one of the trains was. Bells went off in my head and I realized that I could cater his natural curiosity about his beloved trains, and still be 'teaching' him to recognize numbers at the same time!
Get in the Kitchen! I was very hesitant for a while with my son when it came to the kitchen. I worried about the GIANT mess that would be left when he was done "helping". You don't even have to take on the entire project with them! You can start small and let your child help with measuring certain ingredients. You can modify the difficulty of the 'lesson' by talking about the different kinds of measuring cups and seeing what other measurements can also add up to equal one cup, etc.
Computer based math practice problems are helpful in training children how to use math skills in real life while still using tried and true methods of testing. As with the old-school techniques, modern math programs also use multiple choice, fill in the blank and true or false questions to quiz students.
As children become more confident in their math skills, give them worksheets one grade level above their current grade. Help them if necessary, but when students become successful in the upper level workbooks; their confidence will really improve. The seed will be planted early and parents can watch as it grows.