Hi Kulwant, these are great tips as usual. I particularly like the way to tell us to check the google pagerank in case the domain has been banned – that could lower the usefulness of the domain quite a bit. One thing though, don’t you think that buying domains is sometimes immoral? Like sometimes you accidentally buy a domain of somebody elses website who forgot to renew.
Here's a test I have in process.  I bought an old $5 closeout domain from Godaddy TDname expired auction.  I put a quick minisite up and linked to it with a crazy anchor text phrase.  The domain is ranking for that crazy term now.  It's gone through one pagerank update and I'm waiting for a second to come.  Then I'll redirect the domain to another minisite.  I suspect the second site won't rank for the anhor text, but we'll see.  
.ac .ae .af .ag .am .ar .as .at .au .aw .ax .be .bg .bi .bj .bn .bo .br .bw .by .bz .ca .cc .ch .ci .cl .cn .co .cr .cx .cz .de .dk .dm .do .ee .es .fi .fm .fo .fr .gd .gg .gi .gl .gs .gy .hk .hn .hr .ht .hu .id .ie .il .im .in .io .iq .ir .is .it .je .jp .ke .kg .ki .kr .ky .kz .la .lc .li .lt .lu .lv .ly .ma .md .me .mg .mk .mn .ms .mu .mx .nl .nc .nf .ng .no .nu .nz .om .pe .pf .pl .pm .pr .pt .pw .qa .re .ro .rs .ru .rw .sb .sc .se .sg .sh .si .sk .sm .sn .so .st .su .sx .tc .tf .th .tl .tn .to .tr .tv .tw .ua .ug .uk .us .uy .uz .vc .wf .yt .za