I created a "Free Preview" Unit Core Words sheet for the Word Preview activity at the beginning of every Unit. You can fold these sheets and laminate them so students can use a dry erase marker and reuse them throughout the year, or you can print them for each unit. My students really enjoy using them.
I also created Core Word Cards. I only included the Core Words that are introduced in 2nd grade. I put these on rings so students can easily go through them. They need to say the word, spell the word, and write the word. Since I laminate these cards, students can use dry erase markers to write the words. They erase them when it's clean up time for centers. This way they can practice all the words the whole year instead of waiting for them to be introduced. I use Sitton Spelling along with other spelling styles so this is a nice supplement to our spelling program.
The Core Word cards are a great way to check for mastery throughout the year.
Hope you and your students enjoy them!