I've posted this idea before, in another thread. It's somewhat rare, but occasionally one can find a city site that contains 5-8 floodplains and also contains mostly forests as well. I look for sites like these. If the BFC contains 8 forests, that will mitigate to a great extent, the unhealth from the floodplains. I farm the floodplains for rapid growth to a large population. The high pop can then work the forest tiles for hammers while the floodplains supply all the food. The high hammer count enables building infra at a good rate of speed, which then enables one to switch the forest-workers to specialists . . . and back again if necessary. Usually, a granary and aquaduct serves to keep one of these cities out of unhealth or at a very low rate of unhealth, especially considering the number of floodplains worked. Additionally, such cities don't really require a lot of worker-turns to alter the terrain. Clearing the forests isn't either necessary of desirable. Later, roading the forests is advisable and then building lumber mills will crank the production levels up to very good output levels. I've used cities like this to build SS parts. Put factories, coal plants, etc. in them, and the production levels have proven comparable to any specifically production cities built.
