What are the best recommended tips to speed up the drupal

There is no single answer. It depends on whether you are serving mainly logged-in users, whether they are writing or just reading, how much traffic etc. There are good free video presentations from several DrupalCons, for example one at DrupalCon London.

Here are few basic tips based on experience and to some extent my own testing. Most people who care about these things would not run Drupal without installing a bytecode / opcode cache on the server. If a Drupal site has mostly anonymous visitors, I would presonally not comptemplate running it without Varnish on the server. If you are not prepared to spend enough a server where you can use Varnish, you may use Boost module.

When renting a VPS look for Xen virtualisation (which costs more but is worth it) and check the speed of the hard disks, as Drupal is I/O intensive, and if the disks are not fast, go elsewhere. If you are shared hosting be sure to use a Drupal specialist. The bottom line is that if your hosting is cheap is guaranteed to have proportionately lower quality, because any business who gives a high-quality product for a low price loses money. I know, I have lost money on small-scale Drupal hosting for years: but my sites are fast!

You asked about caching, so I left the whole question of front-end performance out. Anyway it is big subject, and there are many tutorials, which can offer far detail than I do here. For some in-depth articles see as well as general tutorials, the more technical blog posts at 3bits.com .