The simplest designs are probably made by covering a surface with various widths and colours of straw, in a single direction.  It is the natural shine of the straw which makes such objects look special.  

Pictures can be made by punching or cutting shapes from straw and sticking onto a surface. It takes very advanced skills to inlay curved shapes into a straw background.  

Here alternate colours of straws were glued horizontally onto a sheet of paper. They were then cut vertically so there were 'stripy' strips These were stuck onto the base making this pattern. To achieve a more even result requires very precise cutting of each original straw.

More successful are patterns like these which are made by sticking and trimming the straw directly onto the surface which you wish to cover. The constantly changing direction of the straw causes light to reflect at different angles from the surface and the results are quite stunning. 

The table. A very basic chipboard object. The design is drawn on the top with pencil.  

The straws are soaked

Each straw is slit along a side and opened out

The straws are allowed to dry out and then pressed flat with the blade of a knife. Some makers prefer to iron their straws flat

Glue is applied to the area to be covered. The straws are laid in parallell lines to cover this area then each side of the shape is trimmed with a craft knife and ruler.

Adjoining shapes are covered in a similar manner but with a change of direction for the straws covering each shape.  

Gradually the entire table is covered with stuck on straw.

When completed, the results are quite spectacular as the light catches and reflects in different directions.  

1. Checkerboard patternPaper strips representing split and pressed straw.

Strips stuck in parallel lines on a backing sheet

Strips cut horizontally.

Newly formed strip moved horizontally to create the start of a checkerboard pattern.

2. Diamond patternPaper strips representing split and pressed straw.

Strips stuck in parallel lines on a backing sheet

Strips cut diagonally

Newly formed strip moved to create pattern. Can be stuck directly onto object being decorated or backing sheet.

3. Zigzag pattern

This needs two sheets , cut at opposite angles.

Strips are laid out vertically, one from one sheet adjoining one from the other sheet. Colours can be joined together (as above)

Colours can be alternated (as above).

4. Irregular strips

You will need individual straws in two colours

Place the straws together in pairs (one of each colour) and cut a wavy line through both straws together.

Place straight edges of straw back to back and match the wavy patterns as shown. These can alternate colour or be glued in a manner to provide a wide strip.