Plan together.
Keep it fair.

Start with dates people can actually make.

Ask each person for the dates they can travel before choosing a stay. Keep a range open until the group agrees. A public holiday may help one traveler and do nothing for another, so check the local calendar for each person's home region. Treat school breaks and seasonal prices as separate questions. A holiday is not proof that a booking will cost more.

Put real options side by side.

For each destination or stay, save its name, country, original listing link, quoted total, currency, and what is included. A screenshot helps when an offer changes, but the original listing remains the source for availability and booking terms. Let everyone vote by name, then record the final choice. A tie needs a group decision, not an automatic winner.

A quote is a planning estimate. It should become an expense only after somebody has actually paid.

Give every job an owner.

A short list beats a long chat thread. Assign food, drinks, transport, documents, and bookings to named people. Let travelers claim tasks themselves, and mark them done when finished. Activities such as a boat day can be proposed before anyone pays for them.

Separate what was spent from who owes whom.

Record each purchase with its payer, amount, currency, date, receipt, and the people who shared it. For example, if one friend pays $240 for a boat shared by four people, each person's share is $60. The payer has covered $60 for themselves and is owed $180 by the other three.

Use nights only for an accommodation cost that truly varies with nights stayed. Do not apply that rule to groceries or fuel unless the group chose it for that specific purchase. Track any repayment already received separately, so the remaining balance does not hide what was originally owed.

Confirm the transfer on both sides.

The sender can mark a payment as sent and attach a screenshot. The recipient confirms what arrived. Until then, it is a claim, not a settled balance. Send money directly to the person who is owed it, and make sure the payment details belong to that recipient.