This can be contentious as many board members feel that they give their time to the organisation and this should be sufficient. But as most people give something to charity (even throwing a coin in a bucket), it seems a good question to ask as to why they should not contribute to the organisation of which they are board members. Giving should be in line with the financial ability of the board member, however small this might be. To say that all board members contribute conveys a powerful message to other prospective funders.
There should also be a policy about board members buying their own tickets to performances/events. Although offering each board member a pair of complimentary tickets helps to ensure that they all see the work, this can mean that the organisation itself is charged for those tickets by the venue. This is another matter that needs to be handled sensitively: if board members can afford to pay they should be encouraged to do so but, if not, discrete arrangements should be made to prevent putting anyone in financial jeopardy.
There should be an expenses policy for board members similar to that for the staff of the organisation, with travel, accommodation and child care covered and expensive fares and taxis discouraged.