There are many directions you could take a natural form project to make it more interesting, meaningful and creative. Here are just a few ideas to get you thinking:
Portraiture
  •  Relationships between people and nature
Architecture
  •  Inspired by nature, e.g. Gaudi
  •  Buildings amongst nature
Bees
  •  Importance of bees in the world
  •  Impact of bees on nature
Life & Death
  •  Skeletons vs flowers
  •  Old versus new
Growth & Decay
  •  Old versus new
  •  Cycle of life
The Environment
  •  Global warming
  •  Pollution / plastics
  •  Deforestation
Plastics & the Environment
  •  Global warming
  •  Nature 'wrapped' in plastic (e.g. photo plants through plastic bags)
  •  Microplastics
Still Life
  •  Bringing the outside inside
  •  Creative compositions
  •  Relationships between objects that have been placed together
The Weather
  •  Sun, rain, snow, storms/wind
  •  Natural disasters
  •  Ice formations
  •  Water droplets on plants and flowers
The Seasons / Passing of Time
  •  Passing of time
  •  Circle of life in nature
  •  Varying colours and light
  •  Linked to the weather
Animals in Nature
  •  Animal habitats
  •  Wild versus domestic
  •  Animal cruelty
  •  Endangered species
Abstract Compositions
  •  Inspired by natural forms
  •  Linked to texture
  •  Influenced by colours in nature
Surrealism / Dreams
  •  Imagination
  •  Storytelling
Insects
  •  Close-up
  •  The important role of insects
  •  Fantasy / Surrealism / Storytelling
  •  Spreading of diseases
Night versus Day
  •  Colour contrasts
  •  Different wildlife
Food
  •  Where food comes from (the food chain)
  •  Ethics (e.g. vegan or supporting local farms)
Furniture Design
  •  Inspired by nature
Close-up / Macro
  •  Linked to texture
Music
  •  Inspired by nature and how it might be represented visually
Love / Romance
  •  Link between flowers and romance
Travel
  •  Cultural identity
  •  Exploration / acquisition of knowledge
Diversity
  •  Different cultures
  •  Colours linked to homophobia, pride, racism or other forms of prejudice
Trees
  •  Age
  •  Passing of time
  •  Strength and stability
  •  Home for wildlife
Gardens
  •  Botany
  •  Allotments
  •  Humans nurturing nature
  •  Wildlife
Occasions
  •  Roses = Valentines
  •  Lilies = Peace
  •  Poppies = Remembrance
Symbolism
  •  What different flowers represent
Intertwined
  •  Connections
  •  Relationships
  •  Intimacy and romance
Growth Mindset
  •  Positivity
  •  Outlooks on life
Geography
  •  Climates
  •  Water cycle
  •  Clouds
  •  Geology
  •  Natural Disasters
Poisonous Plants
  •  Danger
  •  Evil
  •  Deceit
  •  Crime / revenge
Religion & Ethics
  •  Good versus evil
  •  Hope
  •  Sin
  •  Kindness
Storytelling
  •  Imagination
  •  Illustration
Weeds
  •  Beauty of weeds
  •  Difference between weeds and flowers
  •  Importance of weeds for wildlife
This list is not exhaustive, so use it for inspiration but don't let it limit your ideas.
Other ideas
Elyse Dodge
Elyse Dodge
Grace O'Connor
Grace O'Connor
Harriet Mena Hill
Harriet Mena Hill
Henrik Simonsen
Henrik Simonsen
Naoko Shibuya
Naoko Shibuya
Vincent van Gogh
Vincent van Gogh
Juan Sanchez Cotan
Juan Sanchez Cotan
Giuseppe Arcimboldo
Giuseppe Arcimboldo
Yellena James
Yellena James
William Morris
William Morris
Audrey Kawasaki
Audrey Kawasaki
Alex Louisa
Alex Louisa
Kehinde Wiley
Kehinde Wiley
Vie Dunn Harr
Vie Dunn Harr