Choose proven bounty managers. Usually, if the project considers the services of a bounty manager too expensive, it starts the campaign on its own and they can be delayed for a whole year. Bounty manager needs to be paid, and therefore such campaigns usually have a certain period of time, on average it takes 2 months.
And which managers are proven for you? Sometimes (and pretty often actually) even campaigns managed by Tokensute or btcltcdigger are prolonged due to prolonged tokensales, so I can't name a manager that can guarantee that a campaign will and and pay in time. For me it's more important to e sure that a project isn't scam, in this case I can wait for several month.