Hello! It's fantastic that you're planning a trip across Russia to Moscow, Irkutsk, and Vladivostok. Here are some tips to help you prepare for your journey.

Best Time to Visit:
The ideal times to visit Russia would be late spring (May-June) or early fall (September-October) when the weather is milder. Summer can also be a great time to visit, especially in cities like Moscow and Irkutsk. Vladivostok experiences mild warm weather in July and August.

Route and Accessibility:
The most straightforward route is: starting from Moscow, then hopping on the Trans-Siberian Railway to Irkutsk, and finally to Vladivostok. Especially, the train journey provides scenic views of the Russian landscape.

Accommodation and Booking:
You can find a wide range of accommodations in all three cities. It is advisable to book your stay in advance using reliable online platforms like Booking.com or Airbnb. During peak tourist season, accommodations can fill up quickly.

Clothing and Essentials:
Pack layers for variable weather, including waterproof gear for sudden rainfalls and durable shoes for exploring. Don't forget your sunblock and insect repellent too. For travel in the Trans-Siberian Railway, bring essentials like a water bottle, snacks, toiletries, and entertainment options.

Health and Safety:
Ensure you are updated on routine vaccines before every trip. Although Russia does not pose many health risks, it's still advisable to prepare a first-aid kit with essential medications. Always keep an eye on your belongings, especially in touristy areas.

Local Etiquette and Respect:
Russians tend to be reserved and formal in their dealings with strangers. Be respectful of local customs and traditions. Keep in mind that public display of affections might not be well-received. At religious places, dressing modestly is expected.