Having written hundreds of tickets in the past 23 years, I've never lost to these guys.
It's funny that people give advice about the topics they know nothing about.
In fact, the largest (by number of lawyers & employee, revenue), most recognised and well-respected law firm in Singapore is Allen & Gledhill. It has been named Singapore Law Firm of the Year by International Law Review since 2000-2007 (7 years in a row). They are the best one, but for your needs ANY family lawyers should be able to look after you.
Here are my suggestions.
1.) First, plan on how much you want to spend on the lawyer, there is no point asking for a good lawyer who you can't afford.
2.) As a tip, the pre-nuptial agreement should be rather standard and uncomplicated (I have been through the process). You and your partner will need to agree on the terms (e.g. percentage to give/receive, living arrangement after the divorce) BEFORE instructing the lawyer to draft the agreement.
3.) Stay firm with what is agreed, otherwise the lawyer will just try to charge more money to correct the draft. We spent SGD2400 in total, which is on the high end.
4.) As for the divorce, child custody etc; these issues usually are covered in the pre-nuptial which is rather standard. If a legal battle is still necessary; work out your budget and weigh the cost/benefit (emotionally, financially etc). If it is worth it, then you can go all out and hire the best.
5.) Ask for an itemised invoice so you know what you are charged for, the charge can be per minute, 6-min, 10-min block etc. Also document the date/time and topic discussed during each meeting and phone conversation for your own record. If you need to dispute the final charge, the record will really help you.
6.) If the chosen lawyer doesn't provide the standard of service that you'd expect, don't be afraid to voice your discontentment (but do it as it happends not at the end) and refuse to pay for the bad service. Use your itemised invoice to justify what you are willing/not willing to pay for.
7.) Also you need to be wary about the country where you both get married, and whether the marriage is recognised in both bride/groom's country. This might become an issue when things don't work out. Ask your lawyer for more details