Like starting any new venture it is probably best to have a clear plan on how you are going to proceed rather than rushing headlong into a thematic collection.
The advice given by John Hayward on how to embark on a thematic collection is directed at philatelists. However the advice given is equally sound if you wish to include non-philatelic items (e.g. postcards, photographs, ephemera, maps) in your collection.
The choice of topic is yours. Many collectors will choose a theme that relates to an existing interest or occupation, but this is not essential. Starting something completely new can be both exciting and challenging. The only significant ‘pearl of wisdom’ you should heed is to confine yourself to a fairly narrow focus. For example if your choice of topic is ‘Birds’ you might find your collection more manageable if you focus on a particular bird family or geographical area. Even apparently narrow themes can, as your collection progresses, offer unexpected areas of expansion.
Having decided upon your theme it is advisable you first check that there is sufficient material ‘out there’ to enable you to develop your topic. No point embarking on a chosen theme only to discover there is insufficient material available to build a worthwhile collection. At this point a visit to your local library may be advisable to check for suitable reference books that will provide you with necessary factual information to enable you to ‘tell your story’.
If you are coming to thematic collecting as a stamp collector/philatelist then stamp and postmark catalogues will be particularly helpful, but also visit stamp fairs where you will see additional philatelic material including covers, postal stationery and ‘cinderellas’. The national philatelic magazines, Stamp Magazine, All About Stamps, and Gibbons Stamp Monthly list new issues and often have articles relating to thematic collecting.
If you are a postcard collector a visit to a local postcard fair will be informative, most dealers organising their stock under subject headings. Picture Postcard Monthly has interesting articles relating to themed collecting. Sadly it is no longer published, so look for old copies.
If your intention is to include a range of material in your collection then all of the above sources will need considering. Ephemera dealers are often in attendance at postcard fairs and at least two have been attending Stampex in recent years. Clicking on ‘Resources’ on this website will provide you with further information and links to specialist societies and useful websites.
Once you have satisfied yourself that there is enough material available for you to build a collection following your chosen theme then the next step is probably to decide how you are going to store, mount or display your material. Like your choice of theme, this is entirely up to you. If you do not intend to display your collection to anyone other than yourself you only have yourself to please.
If you wish to share your collection with others then you may wish to present your collection following the ‘standard’ format of written up sheets or album pages. The way to see how this is done is to join a local stamp or postcard society where members are displaying their collections. If you later consider entering competitions take a look at exhibits in club, county or national competitions, and look at the advice and exibits on the BTA web pages.