Following on from the English flag keyfob design, here is one of similar size for the Scottish flag of St Andrew (the Scottish national flag).
This one can obviously also be used for any flag which has a similar layout but different colour set. All you have to do is change the colours!
2 Colours, the good old White and Blue... :-)
20-30% infill density for robustly-treated items (for strength) and use brims by default for mating surfaces which need to be perfectly flat (no lifting at the edges) and are thus printed direct on the heatbed. (This density level also gives it a little more tactile weight.)
Fitting it all together
If the sections are printed separately, there ought to be less stringing.
Superglue is the quickest method of securing the two halves together, but be careful not to glue your fingers instead though - and always keep a small pot of debonder or acetone to hand just in case!
When the two halves are secured together, there may be some filing necessary in order to smooth over the seam around the middle edge and finish it properly.