Mr Tomlinson will be giving a presentation on his research and experience in helping families to make their own funeral arrangements at the 2015 Sustainable Skills Summer School.
His interest in the topic began after the death of his father-in-law.
Facing a large bill for transporting the body from Wellington to South Canterbury, Mr Tomlinson, a retired mathematician, began to analyse the usual funeral processes, document the legal requirements, and seek out low-cost alternatives.
As his wife and her brother chose to drive to Wellington and bring back the body themselves, Mr Tomlinson made the funeral arrangements.
He said the family found the whole process therapeutic.
''Afterwards, it dawned on us that we could share our ease and comfort of mind with other people who had similarly expensive bereavements, by writing a wee book,'' he said.
Mr Tomlinson's 24-page booklet, Arranging A Funeral - What You Can Do Yourselves, has gone through three editions and hundreds of copies have been sold.
Mr Tomlinson said the book covered the practicalities of how to manage each part of the process, with advice on issues such as transportation of the deceased, legal issues, sourcing your own coffin, conducting the ceremony and the burial or cremation.
Beyond the question of cost, Mr Tomlinson said many families who shared the funeral tasks found it a touching way to show their love and respect for the deceased.
Mr Tomlinson's presentation in Oamaru is on January 24, from 3.15pm to 4.45pm at Aoraki Polytechnic.
Entry is by donation, with all proceeds going to Transition Oamaru and Waitaki District, organisers of the Sustainable Skills Summer School.
Course details are available at www.sustainableoamaru.org.nz.
