There are a couple hundred ways to make an Oriental Goldbulb, and the Spoilers thread in the Fish Tycoon Guide section of the forum has several resources that you can use to look up those combinations (if you're looking for explicit help). Since there are already lots of lists and charts, I won't duplicate that kind of information here. However, I can give you some general guidance that should give you hints without being a spoiler.

The Goldbulbs are easy to produce by cross-breeding common fish (the ones that you get from common eggs). It's the Oriental fin that can't be obtained by breeding two common fins. Probably the easiest way to get the Oriental fin is to produce a bunch of Goldbulbs (by crossbreeding the right combinations of common fish). Some of those Goldbulbs will likely have common fins, and others will have "second-generation" fins. Then, try crossing the Goldbulbs with "second-generation" fins with the Goldbulbs that have common fins (such as Orange or Green). Good luck!