To dry flowers you can place them in tray of silica gel & put in the microwave, or the simplest way is to hang flowers, grasses and seed-heads to naturally dry.
A keepsake: tips for drying flowers in blog by Olga Sahraoui
Shirley's Tips to Dry and Preserve Flowers
How to dry flowers The Real Flower Company blog
How to preserve flowers with air, silica, and more
How to Dry Flowers - Easy Ways to Dry and Preserve Flowers
How to Dry Flowers and Make a Wreath - Happy Happy Nester
Techniques For Drying Flowers
Nadia Lim's tips for drying flowers (plus 10 easy flowers to dry)
How to Dry Flowers Quickly
How to Dry and Preserve Flowers: 3 Ways + Ideas
How to Preserve Your Own Flowers - Modern Farmer
Why and how to dry your own flowers Sustainable Floristry Blog — The Bali Florist — The Bali Florist
How to Press and Dry Flowers (and Leaves!) : 8 Steps (with Pictures) - Instructables
The Speediest and Easiest Ways to Dry Flowers - Walter Knoll Florist