When giving a time estimate for a project that includes work in areas you don't have experience with how do you estimate?
In most cases it is hard enough to get the estimate right when the project's areas are familiar.
What methods have you used in these cases? How well did they work?
Know what you Know AND Know what you don't Know and you'll be successful.
Use a work breakdown structure (WBS) to get the sub parts of the project/application/whatever. You can provide an est. (to a degree) of the effort to get the knowns complete, as with any project there are the unknowns - identifying them is the first big step. The best next step is to add to the WBS steps to better know those unknowns, for example, if the task is to go BBQ a cheese burger with strips of bacon and you've never BBQ'd bacon before - then you break the job down to getting the ingredients, getting the BBQ, starting the BBQ, etc. and the one thing you don't know - getting/cooking bacon you add some sub-components like: