Though the method can be questioned, I believe one cannot actually be living a true Christian life if one avoids or does not feel the need to preach the Gospel to non-believing friends when they have mingled for a good while.
Or enjoying the Word of God more than any other activities in a secular world. In other words, one wouldn't at one point felt so entertained because of the food or secular based events that one couldn't realize these are all less than the enjoyment of God.
There is no such thing as 'it is not time yet'; only an eager question 'how should I do it now'. While one may delay to seek a more opportune time, but the urge will always haunt oneself.