Hello! That sounds like an exciting trip. Here are some tips for your visit to Nairobi, Mombasa, and Lamu.

Best Time to Visit:
The best time to visit Nairobi, Momba, and Lamu in Kenya is between June to October, and also from January to February when the weather is generally dry and wildlife viewing is at its peak. For beach holidays in Mombasa and Lamu, avoid the April to June period which is the rainy season.

Route and Accessibility:
Fly into Nairobi's Jomo Kenyatta International Airport, the main international gateway. From Nairobi, there are frequent domestic flights to Mombasa and Lamu. Alternatively, you could take the SGR train from Nairobi to Mombasa which is an experience in itself. Lamu is accessible by air and sea; you may take a flight or take a boat from Mombasa.

Accommodation and Booking:
All three locations offer a wide range of accommodations to fit all budgets. Nairobi has numerous international hotel chains, Mombasa offers beach resorts, while Lamu has boutique hotels and guesthouses. It is advised to book your accommodation in advance especially if you're planning to travel during peak seasons.

Clothing and Essentials:
Carry comfortable and breathable clothes. Carry a good pair of walking shoes for safari in Nairobi. For your beach stay in Mombasa and Lamu, lightweight clothing, swimsuits, and beachwear are necessary. Don't forget to pack sunscreen, a hat, and mosquito repellant.

Health and Safety:
Health services are good in Nairobi but can be limited in rural areas. It's recommended to get travel insurance that covers medical evacuation. Yellow fever vaccination is required. Malaria is present; seek advice on malaria prevention measures. Always drink bottled water and avoid raw vegetables. Also, crime can be an issue in large cities like Nairobi and Mombasa, so be aware of your belongings and avoid isolated areas at night.

Local Etiquette and Respect:
Kenyans are friendly and polite. A handshake is the common form of greeting. It's respectful to dress modestly, especially in rural areas and the coast. Tipping is common in restaurants and for tour guides. In Swahili culture, time is seen differently, often referred to as 'African Time', so patience is appreciated.