Morning work is something that I also have had trouble with. I tried worksheets, but some kids would finish early, and some not at all. What worked well was silent reading. After a while, I felt my students wanted to do more, so this is the schedule that I now use for morning work, to keep things interesting.
Monday- Math Manipulatives- the students explore different manipulatives for math. They can build, make shapes and simply explore.
Tuesday- Following directions. I draw a picture of a paper on the board, divided into 4 parts. I write something to write or draw in each square in a different color for each square. They have to draw or write a response in each corner in that designated color.
Wednesday- Writing Wednesday- the students can write something of their choice, a letter, story, report etc. I set out different writing paper each week for them to use.
Thursday- Silent Reading
Friday- Free Choice Friday- The students are given a plain piece of copy paper and they can color, write, draw or anything they choose with their paper.
I hope this helps