Compared to the rest of the Metropolitan Los Angeles market, the Lake Forest region has smaller rates, so you should have no trouble finding a great deal in this depreciated submarket.
In the last 90 days, 37 listings have come on the market, which means listings most likley are going fast. You'll want to be prepared to make an offer immediately. About 5% of the available space in the Lake Forest are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,730 sqft. Most buildings in this area are approximately 2 floors. Most buildings in this area were built in 1999 and are Class B.