I just joined this Lazada bandwagon during mid of this year and I learned few things on how to shop properly in  Lazada. I will share some of it with you guys.

1. Try to add all the items you wish to buy in your wishlist and monitor the price regularly. Before sales and during sales.

2. Dont be greedy. If you think the item you are planning to buy is already cheap just grab it. Don't think it will get cheaper during future sales. I made this mistake few times. Your wishlist will help you on deciding this part.

3. Play around with different voucher & items to maximize your discount. There are certain codes you can use for single item and get maximum discount like RM20, RM25 etc. If there is certain minimum amount should be spent to get the discount, then you may add some other items.

4. Sometimes certain voucher wont work with items on sales. Try to mix non sales item with sales item and use any vouchers. Most of the times it will work. So far its working I guess.

5. Don't do transaction at midnite. Most of the banks will be down this time. You will waste your voucher codes because of unsuccessful payment.

Okey that's all at the moment. Sorry for the long paragraph story.

TLDR :
Guidelines on using Lazada. Things you should do and you shouldn't do.

This is different case. You may do so. Let me give you an example. During one of the sales there was a Air Purifier from Sharp being sold at RM288 only. I didn't buy during that time and was thinking that price will go down further in the next sales. Till now I couldn't find the same price for the similar model.