Review the proper way for students to hold a pen or pencil. Give each student a tissue and ask them to crumple it up, holding it in the hand they write with.
Tell students to press the tissue against their palm with their ring and pinky finger. Tell students to hold the pencil between their remaining three fingers. Demonstrate the proper form.
Show students how to tilt their paper slightly so their writing with have a natural slant to it.
Give students cursive worksheets before you let them write in script freehand. Have them trace each upper and lower-case letter of the alphabet in script each day for about a month so that their hands and fingers are completely familiar with repeating those shapes.
Spend extra time with kids showing them how to write some of the more difficult cursive letters such as F, Q, S and W. Don't pressure fourth graders to get it right. With time they'll be able to naturally do it.
Practice writing six to 12 letters from the alphabet each day in freehand on worksheets that have a double line guide for students to write between. Collect their worksheets.
Examine their worksheets and go over common mistakes that students are making together as a class.