ajay...I think if you use an eyebrow pencil, draw your proposed hairline on your scalp there and then use the cling-film/wrap and trace the line onto that as it will be clearly visible ... the recommended hair sample should be about the `size` of a pencil.....just use an elastic band to hold it together.......it`s for colour-matching purposes......I`d reckon your own hair looks pretty straight so maybe order straight hair to match ? Your own also is growing forward, so follow that
`pattern` for ease of styling. Paul.