For me, the secret is to get in a big hit of protein at breakfast. This means that I have some combo of the following:
flax toast with peanut butter 12g
lo-carb tortilla rolled around lunchmeat, leftover meat from dinner or eggs 15 g
a 'latte' made with vanilla protein shake instead of milk 20 g
AND (not or) a protein shake with 60 - 80 g in the shake alone.
My protein goal is higher than yours, so I try to get in 100 g before lunch.
You can adjust as you need, but the shakes sure do help. I use whey and still get into ketosis. Pre-mixed shakes have 15-20 g and cost about a buck a pop, give or take a quarter depending on brand. I get mine at Wal-Mart, but I might start ordering online so I can really stock up. Carb-solutions makes a Cappuchino flavored one that tastes like the bottled Starbucks drinks. YUMM!
These shakes, btw, are also a vehicle for things like fiber, glutamine, a dash of potassium salt, oils that I don't want to taste, etc.
Oh, yeah - you may hear or read that the body can't assimilate more than 30g of protein at once, and that you will be 'wasting' anything beyond that if you eat it at one sitting. It's not true, so don't worry about it. Nat has the references if you want me to dig them up.
Good luck,
Friday