Print out and laminate these cards. Teach students the meaning of the cards (start with about 4 cards to begin with). As students write in whole group or small group, place the appropriate card next to them. This should encourage students to self-assess, reflect, and edit their own writing.
Consider this: If cards are laminated, have students write their name (dry erase/vis-a-vis) on the back of the cards. As they turn them back in, you can then note which students still need more help with spaces between words, capitalization, etc.