I don't know why your question wasn't answered but there is a lot of info on this elsewhere. If you still need help here is my take.
Choose a Specialty line where you have at least a couple, preferably more 3pt buildings, and at least a couple of 2pt. Buildings. When it comes to Epic Projects 1 pt. are the bane of your existence and most often than not the cause of most failures. Since task difficulty is not weighted for building point value would you rather get 3 points for your 4 cheesecakes or 1? If you are only earning 1 pt you will rapidly outstrip your resources and be forced to the GTHQ where you will probably quickly eat up your cash and time. Hopefully you still have some of your original Speedup Tokens but use them wisely. Trying to do this with only 1pt buildings will be like getting a root canal just to get to Silver don't even think about Gold without serious help from your credit card.
The next element that is equally important is storage. At lvl 30 your storage should be at a minimum of 300 preferably more. You should expect to get multiple orders for multiples of most of the slowest and most difficult to produce items at your level, so you need to have large quantities of these items in storage along with long incubation raw materials. Don't waste storage with easily produced items like steel, wood, nails etc. Use or sell any Specialty Tokens they consume precious storage space and will not be needed. If you sell any Dozer parts, Storage Tokens, etc for max value you can always buy them back and the only net cost is the time needed to repurchase them. Meanwhile you added needed cash to your bank for the Epic run. Think of it as going to the Pawn Shop with your big screen tv getting cash you need and returning the next day and buying it back without paying any vig. Staging yor storage for an Epic run is the exact opposite of what you should do for a Mayors Contest where the focus is on production, and empty space so do Epic runs between Mayors Contests, if you participate, that way some of the mass numbers of products you produce in the contest will fuel your Epic run and the Epic run will lower your inventory in preparation for a Mayors Contest.
Next you will need time. This is an all in adventure so make sure you can focus on this. I've seen different advice on when to start from dawns first light to late at night I personally think mid-day is best this lets you get substantial progress done yet if you start getting low on resources you can restock long production items and materials while you catch a few ZZZ's then grab a cup of Joe and hit it again in a better inventory position.
The first few are the hardest but with proper understanding of which Specialty Buildings to build and expanded storage it becomes relatively easy. I am currently lvl45 with storage maxed at 500, every Specialty line has a minimum of 3 3 point buildings and minimum of 1pt buildings. My typical completion time for a Gold tower is 2-4 hours and I usually don't need to burn Speedup Tokens to do it.
Good Luck.
