It is a good idea to have at least 3 different projects or a variety of sequential steps within the l hour time span.  Students need to be clear of a beginning, middle, and end. Younger students (grades K-2) will need to be reminded of the art instructions and objectives along the way, not just at the beginning.   It is very important not to overdue instruction or "watch" the student too much.  Beginning artists are often apprehensive about their skill levels and will freeze with too much attention.  Encourage and let students know that you are there for advice if needed or desired.
Create projects around students interests-psychological, as well as, physiological.  Create projects that require physical energy, touching, and observing while at the same time meet psychological needs and interests.  Assure students that there is more than one way to create a project.  Illustrate this "vive la difference" by comparing the same subject matter by several artists.  Show how each creates in their own style, and encourage them to develop their own style, rather than compare their work with others in the class.  Celebrate the differences in style by displaying art work and asking students to share or talk about their artwork.
Art projects that encourage students to create a narrative or storytelling aspect that combine language arts with the visual arts are especially accessible to students of all ages.  Cross curriculum art projects that combine various interests of the students are also welcome projects for students who don't understand why they are doing art.  Essential to self confidence is a variety of projects that are drawn from a wide variety of cultural sources.  Multicultural projects create pride, identification, and may lead to further exploration of one's or another's cultural heritage and/or related subject matter. Projects that are fun and interesting help students to gain respect for the workmanship, creativity, and ingenuity of cultures different than their own.  Be sure to include a variety of projects even if the culture is not representative of students in the classroom.  Be sure to include American culture in your melting pot.  Show students a variety of art prints that reflect a number of cultures.
Art projects that foster an awareness of current issues such as the environment are interesting for students and help them to understand their place and their own social responsibility while at the same time provide an area of popular interest.
Be sure also to include art projects that explore aesthetic and process, rather than a finished product, however; it is important to explore with the students the many ways that art is used (the  function) in their society and other cultures.
Above all students should experience a sense of joy and achievement through their creative play.  Students should be reminded that it is normal, and "o.k" to feel some frustration with certain projects, and not to be satisfied with all the art work that they create.  Art like life is a growing process, we learn from our experiences and understand how to make changes the next time.  Discuss examples of how various artists have been challenged by physical limitations, social pressures, financial problems, their own artistic limitations, and a variety of other difficulties.